Regarding the discussion of tackle vs. taser:
Taser was the best option.
The guy shouldn't have been there, would not leave on his own, and thus had to be removed forcibly.
The taser option presented the least potential for harm.
Tackling had the potential to harm both the tackler and the one tackled, with the probability of greater harm to both than a taser shock.
Tasing had the potential to only harm the one tasered, with the probability of less harm than a tackle.
So, overall it seems to have been a good move.