...are we not making a stretch assumption that they actually restarted the engine ?
Well, the source for "both engines operating normally at landing" is the FAA.
The source for the burst tire is the FBI.
Given the relative aviation expertise of those two agencies, we should probably question the burst tire as a more suspect assumption than the engine restart.
Anyway, you can read the AvHerald report and place your bets accordingly....
Incident: United B752 at Newark on Aug 18th 2012, blew tyre on takeoff, both engines "red"