Well, inadvertently is a slightly misleading term in this case:
Tony Allen was running towards the basket to get the rebound or get position and ran right past/through Lawson, his shoulder plowing through Lawson's mostly-stationary face on the way.
It was a deliberate run, and Allen kept his shoulders wide as he ran past Lawson.
You could say it was likely an accident, since players usually don't try to injure others by using shoulders in that fashion, but it wasn't an inadvertent play, since Allen chose to take the path to the basket that included Lawson's body (and face).