Art, I doubt stopping the engine with a piece of rope would hurt anything. The thump may of been forward disengaging or the rope slapping the hull the "last time".
I am assuming you have a direct drive so just engage forward and see if the trans and engine are "locked" together and the same in reverse. Remember in reverse you must hold pressure on the shifter.
If things worked as you were assisting power for the tow I doubt there is any real damage from the incident.
Do check for a bent shaft and as far as the wear and tear on the bearings it's your call as to fixing. I would if you really have a full 1/8 of an inch of slop.
I have seen many wraps on these and others with no damage and yes they all stalled the engines.
Dave Neptune