What options did he have? He couldn't tackle him, so perhaps squib the contest?
Thinking of Hodge on Heppell a few weeks ago, which was just a heavy but unavoidable clash of two blokes contesting the ball.
Probably not a comparable incident. Luke Hodge was following the ball, in fact had it and lost on control of it just before the collision, he then ran into a more or less stationary Heppell. It's not like Heppell had the ball and Hodge came and bumped him. That was more just an accident if anything.
Can try and argue he was just bracing for contact and he may get off. To me it doesn't look like he braces as he doesn't even appear to be going for the ball in the first place. But it is a reasonable argument regardless.