Chasing a shoplifter is not a big thing. It escalated to the point of pulling his weapon when the BG threatened him in the parking lot. I thought he did well and used force equal to the situation. We are talking combat hardened marine here not a once a year arm chair weenie here.
No I would not want to chance a shoplifter but I am a fifty-six year old disabled man. If it was more serious, like seeing the original assault I would be much more inclined it intervene.
Just my thoughts