Chicken Wing HTB

Saw a couple last night, including the Daicos one on the wing, and just now watching Hawks Freo, where a player has 1 arm free that's holding the ball, gets their other pinned or chicken-winged and can't access their feet. Inevitably, these get paid HTB regardless of prior. I don't get it. If you've got no legal way to dispose of it, and had no prior, how is it any different to having the ball pinned against you? We're happy balling that up because it can't be disposed of, but leave 1 arm loose and you're screwed.