Dignam a mob mole? Interesting.

Of course, if that was ever intended, my only problem would be this: If the mob has Dignam the mole, why need to send another in Damon into the same HQ?

Maybe Dignam though is a mob mole of another crime outfit outside of Nicholson's.

Anyway, I still think the guy was a cop who got pissed that his boss/mentor and partner were killed, and he got his revenge.