Ernest Fitzgerald, the most celebrated "whistle-blower" of our time, achieved a sort of civic sainthood for exposing cost overruns on the C5A Air Force transport plane long before he sued Richard Nixon for having fired him. But as Fitzgerald's inevitable (and in the era of rising defense budgets, perhaps salutary) beatification proceeds, a few curious facts about his case need to be noted.

In an out-of-court settlement, Fitzgerald collected $141,000 in advance from the president he accuses of wronging him. It was a lucky break. For the U.S. Supreme Court, after a term-long and apparently strenuous internal debate, held the other day that a president enjoys "absolute" immunity to civil-damage claims of the kind Fitzgerald lodged five years ago.

The 5-4 decision is eminently sound -- indispensable, in fact, to effective presidential administration. A president, like a judge (who also enjoys such immunity in the pursuit of his duties), faces innumerable situations in which there is potential for offending subordinates. His authority could be impaired, even paralyzed, if he had to worry constantly that the cost of an administrative error might be $141,000 -- or more.

The oddity of the case is the nearly universal assumption that Richard Nixon indeed "cashiered" Fitzerald for merely telling the truth to a congressional committee about lax use of the public's money by the Air Force. This impression is clouded, if not erased, by Justice Powell's careful recital of the factual history of the C5A episode and its 14-year sequel. It was lower-level staff, subordinates of then-Air Force Secretary Harold Brown, who came up in the fall of 1968 with the bright idea of removing Fitzgerald by the device of "RIFfing" his job. His actual removal did not occur for another year, after Nixon had taken office, but it has the look of bureaucratic momentum more than presidential highhandedness. Nixon, it further appears, was utterly confused when he boasted to a news conference in 1973 that the Fitzgerald dismissal was "a decision that was submitted to me." The infamous Nixon tapes, usually regarded as unimpeachable proof of Nixon miscreancy, show in this case that the boast was inaccurate. John Ehrlichman told Nixon so, and the claim was retracted. The record also shows that the Civil Service Commission, though it found that Fitzgerald had been irregularly discharged, discounted the theory that he had been penalized for "whistle-blowing" and doubted his claim that he was not "Senator Proxmire's boy in the Air Force."

These oddities and ambiguities of the Fitzgerald case have been studiously ignored. They make it all the more fortunate that the Supreme Court was not drawn by Fitzgerald's claim against Nixon into taking a damaging swipe at presidential authority.

Suppose, just to be supposing, that it really had been vital to the national defense for Lyndon Johnson or Richard Nixon to see that a certain plane was built, regardless of cost, but that either or both had to tolerate guerrilla warfare against it at lower levels of executive officialdom for fear of being hauled into court later. Maybe the C5A was not that plane, nor the presidential judgment that critical. But either could have been. That presidential judgment might, be thus thwarted by insular and parochial subordinates, collaborating with congressional penny-pinchers, was too much for that old Air Force officer, Justice Lewis Powell. Hiw argument, fortunately, won the day -- narrowly.