Whether or not they fell is irrelevant. What’s relevant is that they were concerned it could happen.
Assuming that was a legit concern, I’d have no problem with him being dragged. I don’t see that as any different than dragging someone, even with a possible neck/spine injury, out of a car after a chase if they noticed it was on fire. It would be equally irrelevant whether or not the fire spread to the point that the suspect would be burned, just that the potential was there.
Plus, it’s better for everyone (the suspect, the police, EMTs, FD etc) to get him out of that area before there’s a problem rather than waiting to see if they actually fall and find yourself having to wait for the utility company to get someone out there to de-energize the lines.
As for whether or not the lines fell, I don’t know, but if you watch the video, it’s not that he hit the pole, he broke it. All the weight of the pole, or at least the part above ground, is now hanging from the wires. And, it does look like they’re genuinely trying to get him out of the way, not rough him up.
Honestly, if they wanted revenge, they’d be better off leaving him where he was. No one would think twice if they said they left him there for his own safety (possible spine injuries) and theirs (the overhead wires), until EMTs, FD and possibly the utility company arrived on the scene. They’re the ones trained for this. Meanwhile, they’d be using it as an excuse not to provide rescue services, possibly meaning he died when he could have been saved.
Ask yourself this. Imagine that was you. You jumped* out of a moving car, hit your head like that, but somehow you survived it and you didn’t do any spine/neck damage. Would you rather the police dragged you away, risking paralysis or leave you there, un-paralyzed, but with electric lines operating at 10’s or 100’s of thousands of volts, ready to find a path to ground, through you.
IOW, possible paralysis or guaranteed death.
*Doesn’t even have to be that you jumped, I’m not implying you were running from the police. We could even change that to “Imagine you got hit by a car going 60mph” and the car hit the pole. You want the cops to drag you out of the way or leave you?