Re all the comments about Captains,( this site used to be about 50% Captains posting....feels like about 2% now) I think there will be a lesson that current Airline Captains can take from this once a factual report is released and it will be thus;
Although ground staff and Police are usually quite good at their jobs, if a passenger is to be removed the Captain should hold a two minute meeting with those involved to set expectations about how the removal will be conducted and set a clear expectation that another meeting will be held prior to using any form of physical coercion.
I imagine the Captain involved just assumed everyone would do their job in a professional manner and it didn't turn out that way.