YS240
The natural inclination of the people involved was to continue fighting. Magic wasn't used to physically restrain them like a Bigby type spell. Magic was used on the minds of the victims to prevent them from acting according to their natural inclinations, a 4th law violation*. As a side note, the 4th law is all about what the road to hell is paved with.
*Sponsored magic issues aside.
Again, IMO it didn't actually cause any lasting affects, it was a Block. Once dropped they were free to go right on being angry and hostile. Their minds weren't changed. They weren't overcome and caused to take consequences dictating they were "calm and non-hostile", they were actively restrained. It was the mental equivalent of a physical restraint, once removed they were free to go right back to killing each other.
Like handcuffs or straight jackets, yes prolonged exsposure could be damaging, but a quick restraint isn't likely to do any damage.
Personally, I'd say it doesn't Break the Fourth Law and apply Lawbreaker, but it sure as hell would look like a Fourth Law break to any witnessing Wardens.
I'd also have a talk with my group and go with the consensus. Damn, The Laws of Magic are almost as bad as D&D Alignments.
He could pretty easily come down with Post traumatic stress disorder or some other mental issues or even a loss of confidence in his ability and will have to take that desk job instead of the beat cop he always wanted to be.
Eh. He took no stress from it and the Human Psyche is a lot less fragile than Harry Dresden tries to make it out to be.
I'd say given a few days the events would become a bit muddy for the cops involved, some more so than others.