Excellent job by the flightcrew.
By the way, American Airlines never closed their maintenance hangar in Tulsa, whereas several US major airlines outsource all of their heavy maintenance checks.
And if your airline allows heavy maintenance to be performed in another country, only the Supervisor Technician is required to have the US FAA A&P license.
The other (anywhere from 5-80) mechanics/engineers are not required to have the qualification.