Or was it supposed to not be personal? When the plane explosion happens, Alex is treated as a suspect, although more from Schreck than Weine. Schreck antagonizes him from the get, and when they take him in for questioning, when Ms. Lewton calls the cops on him, he even shoves him into the back seat. He's the black agent who works with Weine, the white agent.
Weine is the first one to actually let him go based on the fact that he clearly showed to them that he had no control of the deaths, giving away Alex's innocence, yet Schreck clearly seems to want to keep Alex detained against his own will, even when evidence doesn't point to him. Or was this some good cop, bad cop thing? It seemed kinda personal.