...who needs executioners?
It seems to me that an incubi with even a moderate level of skill should be able to protect himself from a chop happy being, but that would also involve outing himself to his other team-mates , who would at best be confused long enough for head to roll, at worst hold him down for the process. I'm unsure how long the group have been friends/colleagues, hopefully long enough to be able to work out that this is the real Jason and not an imposter.
From a common sense point of view the other incubi coming clean would help things along, but where's the fun in that?
It may be that he's just playing for sympathy, or possibly overreacting like 'Cubi do. If he really felt his life was in danger, chances are he'd flee.