Cops are the bad guys until you need them
I live in British Columbia, Canada and am a paramedic
I see some problems with the man's side of the story - first off I doubt you'd have to shock him 3 times to subdue him - of course maybe the RMCP went a little overboard there but his - I don't know what happened I'm hypoxic (low oxygen levels) it caused my to go crazy seems pretty far fetched indeed.
First off he's in the hospital on O2 so he's levels would be under control. Second he just have heart surgery so he would have be hooked up to a monitor that shows his vitals - one of which being how much O2 is in the blood - an alarm would have went off if his levels were low prior to him going "crazy" as it were and the staff would have come check on him. He would have been in the cardiac ward which has more staff than most other wards so the alarm would have been noticed.
Third, I've worked with the RCMP and they are not the trigger happy people everyone thinks there are - heck I've tried to get them to taser people and they won't go for it. I've been on those calls were the patients are out of control and tasering is considered the last option - well just above shooting which is how things were dealt with in the old days. Hmmm 1 or 2 people died from tazering - 90% of people shot died in the past - sounds like tasering saves lives.