Stephen Baldwin — Photog Incident NOT Alec’s Fault

Stephen Baldwin had big bro Alec Baldwin“s back last night … telling our sources that his brother is not to blame for laying that alleged smackdown on a photographer earlier this week.

The Baldwin brother (Stephen, that is) was outside Katsuya restaurant in L.A. Friday night … where he gave us some insights into Alec”s confrontation with a NY Daily News photog … and he”s adamant Alec has changed his ways.

Stephen says his brother wouldn”t get violent without good reason. He adds … if a pap instigated a “situation” … any reaction is pure human nature.