Since the pandemic I have gotten friendly with a co worker.

In a three way phone conversation (with another friend and co worker) he opened up a little and told some stories from a mutual boss we had. I was aware he has worked for this boss but had no idea it had been for a year.

This boss was abusive to me (and it turns out everyone else).

But, this co worker friend mentioned that the exact same abuse that was lavished on me was lavished on him for a year -- BEFORE -- just before -- I came to work there. The co worker went on to a non abusive boss. But it got me thinking about how this co worker didn't really try to help me when I arrived. No kind words, no tips for the unwary. When this co worker covered for me he didn't do any of the "covering" and I usually got hammered when I came back in that this wasn't done or that wasn't done.

This could be forgiven when I assumed the co worker didn't know the true extent of it but now, he admitted he knew exactly what would happen. He had been subjected to it himself.

On the one hand of course I don't expect him to ride in and banish my abusers but on the other hand now, thinking back, I never really got a heads up (like assistance with my work or suggesting that I get another job) for years.

Am I overreacting? Or am I wisely realizing that this guy is just out for himself and I should stop assisting him.