It just occurred to me while reviewing this play for the last 10 minutes that what happened at the rim is irrelevant.
NBA Rulebook > COMMENTS ON THE RULES > II. BASIC PRINCIPLES > A. CONTACT SITUATIONS > 2. Guarding an Opponent:
A player who extends a hand, forearm, shoulder, hip or leg into the path of an opponent and thereby causes contact is not considered to have a legal position in the path of an opponent.
If followed per the rulebook the refs not only could’ve called a foul on Joe Johnson, but they should’ve called a foul on Mason Plumlee for initiating contact via extending his left hand into LeBron’s chest.
We’ve also spent a lot of time this year talking about the “rule of verticality” and it seems Plumlee violated that one as well. Plumlee, being the player who initiated contact via an extended arm (making verticality impossible) should’ve been assessed some sort of foul.