Seems like he was tasered and died due to weak heart rather being outright shot with a gun.
And if he was inebriated as the witness indicated, the use of a taser was probably not a good idea. Not to mention, how is he a threat if he's so faded that he's stumbling forward in his approach towards the police? If multiple officers, let alone one officer, can't handle a man so faded that he can barely stand and feel the need to utilize a taser, they shouldn't be cops.
edit post: It reminds me of the 80 year old man shot while holding a knife because he was a threat. It's preposterous.