my opinion, though I havent looked at any stats to back this up, is that
once armed with a (supposedly) less lethal weapon such as the taser- the
police are much more likely to use it than to have to wrestle the guy down (even though theres 4 of them).

although it may not have been the taser that caused his death, according to the man who filmed the incident one of the cops had his knee on the mans neck and at one point in the video you see all his weight on it as his other leg is off the ground.

of course police work is dangerous, however there has been a string of incidents which resulted in the death people in custody - and no real accountability..
for instance a young man with no criminal past - arrested for drinking in a public place - sent to the drunk tank - ends up being shot in the back of the head by the one police officer on duty in the jail that night. The coroners and subsequent enquiry found no guilt - the police officer was afraid for his life ..

currently theres an inquiry into the death of an aboriginal man - who after being taken to a drunk tank - is dragged out unconscious, in his soaking wet clothes into below zero weather and dies of exposure.
The 2 police officers involved were 'punished' by having 2 days suspension (paid leave). Frank Paul Inquiry

elsewhere in Saskatchewan where the weather often drops below 40 in winter,
there was a number of first nations (aboriginal) men who died of exposure outside city limits.. Later it came out that a group of police officers regularly dropped people off in the middle of nowhere.. again it was covered up for years and even after a public inquiry - the only real punishment was that two were kicked off the force..Stone Child Inquiry