I've always seen House as a fucked up individual and his previous lashings out were within that fucked in spectrum that operates within him. This is House when he truly lets go of his emotions.

YES, THIS. The potential has *always* been there. As Cuddy said in "Finding Judas," House holds himself back. His leg pain has been a sign of his internalized anger since S2. I agree, as disappointing and nasty and vicious as it was, it was in line with House's character.