Except that the "court reporter" was wearing an open-necked Hawaiian shirt and sipping a Coke, the scene had all the judicial trappings of a court proceeding, a messy divorce perhaps: the witness perspiring nervously in the box; opposing attorneys at their tables with their clients and a cross-fire of often emotional testimony and biting cross-examination.

It was not a courtroom, however, but a Civil Service Commission employe appeals hearing room on H Street NW, closed to the public.

A federal manager was trying to persuade a judge-like, white-haired hearing examiner that, a year or so ago, he had good reason to fire one of his employees, a GS-14 professional, for imcompetence.

The employe was contesting the firing, seeking reinstatement with back pay. In the process, he and his boss were bitterly rehashing all their old differences.

This appeal hearing was part of an increasingly complicated, court-like system that was intended, when the original civil service system was drafted, to apportion rewards and discipline among U.S. workers. Instead, many federal managers view it as the Loach Ness monster of the bureaucracy - a costly, predatory protector and leveler of civil servants whose coils of red tape are more to be feared than all but the most dreadfully worthless employe.

"The reward structure is such that those who are productive are indistinguishable from those who aren't, said Barry Kefauver, personnel director at the Federal Trade Commission. "The 'high cost of canning' is much greater than (the cost of) shoving the person off in a corner and letting them waste away at $35,000 a year, as far as the public interest is concerned."

The House this week followed the Senate in overwhelming approval of President Carter's proposals to overhaul the 100-year-old civil service system.

The most controversial differeence between the two versions to be worked out by House-Senate conferees next week, officials say, is in the section dealing with the amount of proof a federal employer needs in order to sustain a firing or other action against an employe.

Much of the controversy, and considerable confusion, has centered on the so-called rights that go with a federal job. The unions and some members of Congress have argued that a federal employe has a "property right" to his federal job. The subject has thrown the courts into confusion in recent years, experts say.

"It is a ghastly area," said Roy Schotland, an administrative law expert at Georgetown University Law School. "The courts have said that people do have a property right to their jobs but then the question becomes, 'What of it?' It doesn't mean you own the job . . . It means you're entitled to a certain kind of process."

While federal officers say they look to court interpretations to decided such questions, Schotland said it is up to Congress, ultimately, to spell out what kind of procedural rights it deems appropriate.

An employe who alleals a firing can win reinstatement with back pay unless the agency can show that a "preponderance" of the evidence is against him. The House version of the bill retains that standard, while the Senate makes it a bit easier on the boss in some cases, requiring him to present only "substantial" evidence.

The current complex and time-consuming procedures justifiably or not, intimidate managers and their employes alike, breeding apathy and inefficiency, according to the proponents of change.

Federal employes' unions and their allies agree that the federal process takes too long and is too complicated. They also contend that it favors management, rather than the employe.

A spokesman for the National Treasury Employes Union cites the case of two low-ranking Internal Revenue Service employes who were fired for filling improper income tax returns and were reinstated, with back pay, only after a four-year legal battle all the way to the U.S. Court of Claims.

"Neither could find employment in private industry during that period," the union official said, "and were forced to live on welfare benefits."

On the other hand, the supporters of the Carter plan come back with their own stock of horrible examples at the other extreme. The cite, for example, an agency that fired and employe for beating the supervisor with a baseball bat. The Civil Service Commission's Federal Employee Appeals Authority overturned the firing on the grounds that the agency had not given the employe adequate notice of the firing, a recent GAO report said. The agency had to reinstate the employe with eight months' back pay.

Of 580 reversals in 1977, 355 were on such procedural rather than substantive grounds, records show.

The biggest problems of all, to many federal managers, arise from discrimination cases, which follow a different administrative course. "You always hesitate even longer before you fire a woman or a black," said one manager.

Many federal employes say privately that they would go along with any plan that will get their bosses to boot out incompetent or marginal workers. "We have to cover their posteriors by doing their work for them," one employe said.

Many others expressed doubt that any system can force a boss to do his duty. Several cited their ultimate boss, the president, as an example, pointing to his recent hiring for a White House job a Robert Griffin, a fired General Services Administration official, who happened to be a "crony" of House Speaker Thomas P. O'Neill.