One by one, President Reagan's top agency officials appeared before the Senate subcommittee to argue that their budgets should be cut, that they had too many wasteful programs, that they didn't really need so much money.

All this changed when Earl Oliver took the witness seat. Oliver, one of the three presidential appointees to the Railroad Retirement Board, said the board's $65 million budget request was a sham.

The board is paying benefits to hundreds of dead people, he said. Its programs are riddled with waste, fraud and abuse. And if the Office of Management and Budget succeeds in chopping the staff further, he said, "we'll fall flat on our faces."

It had the makings of a dramatic moment for the Senate Appropriations subcommittee on labor, health and human services, education and related agencies.

But few senators were present on April 30 to hear Oliver, and even fewer seem to care about the railroad board. But that hasn't stopped the subcommittee from becoming involved in such matters as how many employes the board should have.

To be sure, there is little publicity value in dealing with a dusty corner of the bureaucracy that oversees industry-funded benefits. But the senators jealously guard their power to dictate such line-item decisions.

Oliver has repeatedly complained to the subcommittee that a 25 percent reduction in the agency's 2,000-person staff has devastated its operations. And for three years, subcommittee Chairman Lowell P. Weicker Jr. (R-Conn.) and his House counterparts have pushed through provisions barring the administration from cutting the railroad board's staff below its current level of 1,578.

This year, the president's budget would cut the staff further, to 1,420.

Oliver, citing a series of federal audits, said that:

*In a 2 1/2-year period, the board paid more than $4 million in benefits to 956 people who, it was discovered later, were dead.

*Board examiners spend an average of 67 minutes deciding lifetime disability awards, and auditors found that a third of those receiving the awards were not disabled.

*The board routinely fails to check with employers before paying unemployment benefits to railroad employes who say they are out of work.

OMB spokesman Edwin L. Dale Jr. said the board can get by with fewer employes because its caseload is expected to decline. "We've felt for a long time that they have very sloppy management," Dale said. "They haven't focused their resources where the waste, fraud and abuse are."

Oliver, a Carter administration appointee whose term has lapsed, was replaced in the $70,000 job this month. Oliver said White House aides told him he was removed because of his testimony before Weicker's subcommittee.

In late April, Richard P. Kusserow, the inspector general at the Health and Human Services Department, sent Weicker a seemingly routine letter about Medicaid audits. But the events that produced the letter were anything but routine.

The first shot was fired in March, when Kusserow appeared before the panel to justify his budget. Weicker quickly peppered him with questions about why his auditors were trying to recoup $34 million that seven states had spent on services for the mentally retarded.

Many witnesses cower before such onslaughts from the chairman. But Kusserow, a former FBI agent, stood his ground.

"I was married for 12 years to a social worker who worked with the developmentally disabled and adult retarded," Kusserow said . . . . "I have a very strong personal commitment to that area from firsthand experience."

Kusserow said federal law prohibits the states from spending Medicaid money on "educational" activities for the mentally retarded. He said some state officials were improperly charging the program for the cost of trying to educate patients who "are retarded beyond the ability to train."

That brought an angry response from Weicker, who has a son with Down's syndrome. He said the state facilities were trying to train retarded patients to hold up their heads so they could learn to feed themselves. How could Kusserow's auditors be so narrow-minded as to disallow such basic services?

"The almighty God of this administration . . . is how to save a buck," Weicker declared.

After the hearing, Kusserow and Weicker's staff exchanged sharp words in the hallway. Many HHS auditors resented their work being second-guessed by a senator who likes to crusade on behalf of the handicapped. The two sides held a series of tense meetings, and Weicker threatened to call another hearing to interrogate Kusserow.

Finally, Kusserow gave in. He wrote Weicker a letter defending his staff's work but promising to halt the disputed audits until a pending court case on the issue was resolved. Weicker, in turn, agreed not to air the showdown publicly.

Weicker showed no such restraint at another April hearing, where he castigated Education Secretary William J. Bennett for naming Eileen Marie Gardner as his special assistant.

As reporters scribbled furiously, Weicker quoted at length from Gardner articles about the handicapped. He attacked her for saying that handicapped people "selfishly drained resources from the normal school population." Bennett initially defended Gardner, but she resigned after two days of headlines.

What few realized was the detective work required to produce the confrontation. Weicker's aides knew Gardner's views had long been anathema to activists for the handicapped, and they knew Bennett was planning to hire her. But they didn't know when.

Each day Weicker's staff checked with the Education Department to find out whether Gardner had been hired. The day before the April 16 hearing on the department's budget, Bennett put her on the payroll. The staff, assured of maximum publicity for their assault, told Weicker about Gardner a half-hour before the hearing began.

"If Bennett had waited a couple more days to hire Gardner, she'd probably still be there," a subcommittee official said.

On May 21, Labor Secretary William E. Brock announced that the department had dropped plans to close regional offices in Boston, Kansas City and Seattle.

The timing was no accident. Weicker previously had berated Acting Secretary Ford B. Ford for trying to downgrade the offices and cut 196 jobs. Weicker was particularly concerned that his home state would get short shrift if the Boston office was abolished.

Weicker saw a new opportunity when Brock, a consummate politician, took office in April, and this time the senator received a little help from the House Appropriations Committee. Rep. Norman D. Dicks (D-Wash.), who represents Seattle, announced he would offer an amendment at a May 21 markup session that would block the department from closing the three offices.

Faced with an embarrassing rebuff, Brock phoned the appropriations committees that morning. He later announced that he was not closing the offices because they were "vital to too many citizens." Everyone on Capitol Hill knew which citizens he meant.