I'm in two minds about Uncle Arnold. Whether he truly believes his nephew and was thinking he'd massively help the case by hiring these guys to help prove OP's innocence or could he have thought the case wasn't going OP's way and releasing this was a last ditch attempt to cause a mistrial?
With the smirk he sports daily, all day... I'd say he thinks he's already bought OP's ticket out of jail, this is just to court public opinion to help the "golden boy" get back on his feet, so to speak.