UPDATE 1-Top US arms buyer sees no mistakes in tanker pick

(Adds details, quotes, background)

By Jim Wolf

WASHINGTON, June 5 (Reuters) - The U.S. Air Force's choice of a Northrop Grumman Corp (NOC.N)-EADS (EAD.PA) team over Boeing Co (BA.N) to start building a new aerial refueling fleet ought not be undone over a possible small judgment call with minimal impact on the $35 billion decision, the Pentagon's top weapons buyer said on Thursday.

"In my look at it, I have not seen mistakes" by the Air Force selection team, John Young, the Defense Department acquisition chief, told a small group of reporters.

The Air Force awarded the contract to Northrop and Airbus parent EADS on Feb. 29. Boeing protested to the Government Accountability Office, or GAO, which reviews challenges to federal contract awards. The GAO is due to make a recommendation to the Air Force by June 19.

"Everything I've seen and heard is that GAO is analyzing all the facts in great detail," Young said. "I hope the decision will be viewed as reasonable."

"I certainly hope, though, (that) if there's some small area of judgment that probably would not have a material impact on the outcome that we won't undo the whole thing over that," he added.

In some spots, "you're going to find judgment calls," Young added. "These are people, This is not binary and digital," he added, referring to decisions made by the selection team. (Reporting by Jim Wolf; Editing by Tim Dobbyn)