It is a hallmark of Jeff Fisher teams: play to the echo of the whistle. Be chippy. Most def. be physical. The night before the Skins and Rams game, Mike Shannahan told his team to keep their cool...of course they did not as receiver Josh Morgan got a crucial penalty for a retaliation shot at Finnegan.
Remember Fisher played for Buddy Ryan and Fisher's understudy is none other than Gregg Williams. Fisher still has not let Williams go. I am sure there is a friendship, but I wonder if Fisher had any bounties going on in their time in Tennessee.
Fisher is a damn good NFL coach. He is doing good things right now. However, the OP is correct in pointing out that his teams walk the line of hard play and dirty.
Get over fisher. He's not a good coach bro. At all.