I agree with Apple, Michael's hope for a legitimate and honorable life was shattered with the publicity generated by the congressional hearings; Roth's doing.
He's a mobster who out-smarted the feds, not an outstanding citizen!
Its also a public message to those who might think of going after him. Michael was portrayed brilliantly, but as the human that he is... he must sometimes "slip", or loose his temper, or go irrational, as all humans do.

As for talking to the group altogether... well, "desperate times call for desperate measures"... if you recall the scene; they were all seated except Michael, who was restless and animated out of agitation, and Tom's ill-timed comment was the little nudge to get him off; he may not have intended to talk so openly, but Tom's defeatist and skeptical approach got to him.