He was extremely soft when it came to Peter Savino...
Well, he obviously made a big mistake with Savino; probably the biggest mistake of his career. But I wouldn't call him soft. If Savino wasn't a protected witness, Chin would have gotten to him long before the cancer did. I can guarantee you that.
But I get what you're saying. Chin did have a soft spot for the guy, in that he trusted him enough to deal with him directly, even though he was a mere associate. That's a big no-no. It was the biggest mistake of Chin's career, and he died in prison because of it.