To be honest, Id be happy to "winch" off a tow ball with a dampener in that situation Rod , tow balls are designed to pull stuff, (you would not think twice about hooking up a car trailer and towing a car) its the shock loads from snatching the should be avoided, what you did sounds safer again, going around the tow bar itself.
Knowing GH and going from your description, he was not in some huge bog hole anyway, and was obviously just on slippery clay mud, its like ice, so he just had no traction, not have the added suction of being stuck in mud bog, greatly reduces loads for a recovery.
As for if you should have helped, well, its good Karma my friend, never leave a man behind, and some one else may have come along and snatched off the tow ball etc.