Billy's Spanish response to the gatekeeper as they enter the prison is off enough that it should have alerted the guard he was not engaging with a fellow countryman, despite his wearing same uniform.
Windshields wouldn't shatter as the one on the van did when a thug tossed a guy through it. Obvious stunt glass more suited to buildings than a vehicle.
It made no sense for Jim to remove his hood twice during his nighttime recon mission, since being seen by any of the goons he was encountering would blow his cover.