I never compared the two, but since you ask, they are completely different situations. The cop is doing a public service, and I acknowledge the fact that it's a difficult job. He's making an arrest, and it's hardly the first time we've seen cops put their knee on a suspects neck. He fucked up, big time, and I already said they need to throw the book at him.
The other is just criminal thugs breaking into a business and attacking an unarmed small lady, beating her, and hitting her with a 2 by 4. I would consider that worse because of the lack of morals involved, but that's just my opinion. If you want to break into a business and beat defenseless people with weapons, you probably deserve to get shot and killed.