Just a blatantly stupid hit. Should have been a penalty, I don't know about a 5 minute major because it wasn't incredibly extreme like others I've seen . And I only say this because in one of the angles, Ghost actually turns his back slightly to make the hit a lot worst + Komarov didn't full on-tackle or throw him into the boards, I don't think he went full throttle there....he was probably surprised a bit by how easily off-balance Ghost was there. To be fair to Ghost, he probably didn't expect a hit there either.
All that said, hard to dispute if we're using hindsight and the end-result of Ghost possibly getting hurt.
Hits like that should receive a minimum of 2-3 games on first offense and worst for repeat offenders.