I agree with Ranger One - if I had been on that flight, I would do my utmost to bring charges of false imprisonment.. it was a ridiculous abuse of position and if this had happened anywhere else, anyone holding passengers against their will would be dismissed on the spot, and rightly so.
Also, if the man was that self important and pompous, I would have to question his ability to work an emergency
with the FO. Talking of which, I wonder what, if anything, the FO said to challenge the Captain's apparent departure from sanity.
Ranting aside, I think probably the best solution to smokers in the loo would be to put sprinklers in there !