Right or wrong, I know I would feel guilty before God if in my duties, it took 71 hits to control a guy.
If it took that many, then they were using the wrong weapons and ammo in the situation.
I concur with your assessment that he was probably dead after the first 7 rounds, or if not, probably would have died from loss of fluids after the first few.
They did not hit him 71 times, it was seven. Again, combat is fluid and not all rounds are going to find their mark, nor can you reasonably expect them to when it goes loud. Looking at the pictures, I suspect they engaged him started backing out and continued to engage through the door.
One of the deputies fell and apparently the others thought he was shot. Well, you can imagine what traspired next.
I don’t know what weapons they are issued but I am fairly certain that with a team as large as they are, they are not using substandard weapons or ammunition. This team might even be a full time team, I don’t know.