Well, assuming that's the entire email that was sent, some basic level of empathy might not have been amiss. "So sorry about that, are you okay? We'll pay for the glasses. Obviously this behavior isn't okay; we've discussed it and we're going to try..."

Assuming this is anything above pre-k, I'd be hoping that the parents would respond with "Sorry we've spoken with him about this unacceptable behavior / we're connecting with a children's counselor to address anger issues / etc."

If it's at the point that I'm getting punched in the face at work, I might also be annoyed at their response being

That's a false dichotomy. Reasonable responses are framed as either "kid has low blood sugar so I'm packing him a banana", or "sorry, we'll beat him with jumper cables". There's like 50 reasonable responses between those extremes.

Do you think that if you were teaching a class and one of the students punched you in the face so hard that they broke your expensive prescription eyewear, that you would actually just dust yourself off and go, "oh dear, you poor thing - are you acting out due to low blood sugar? I can go get you a banana".

You really think that's a reasonable response for any human?

Hear me out, maybe we need to teach the kid that hitting isn't okay even when they're hungry

I'm hoping this was cut off from a longer email, but if it was not she probably could've at least expected the parents to apologize on behalf of their kid, ensure they spoke to their kid about why it's inappropriate to hit people, probably have the kid apologize, and depending on some other factors offer some kind of compensation for the glasses at least as a token gesture.

If your kid hit someone in the face hard enough to break their glasses and your only response is maybe they were hungry here's how I can address that, I can potentially see why they might have done it in the first place.

It probably would have been more reassuring to get stronger protection guarantees on the teacher's side. Unless the plan was for the teacher to slot in as the punchable feedback loop until they eventually "get him back on track"?

One key aspect to conflict resolution is to acknowledge the other side’s grievances, offer any appropriate apologies (being punched in the face and have glasses broken certainly warrants a heartfelt apology), and if necessary offer any remediation that would satisfy the other party (e.g. offering to pay for the broken glasses, and most importantly, suggesting that they spoke to their child to explain that behavior is inappropriate and unacceptable).

These parents did none of that, and just waved it off as if it’s okay for the kid to do this kind of thing “because they’re hungry”.

The issue is the parents’ refusal to take responsibility for their own child’s behavior.

Which is one of the tentpole requirement of being a parent.

Functional people don't punch their teacher in the face because they don't have enough to eat. He may have had low blood sugar AND a behavioral or mental issue that needs to be addressed.

At minimum I would expect a letter from the kid as to what they did was wrong and an apology from both parents and kid. I would expect an offer to pay for the glasses. I would expect the kid to be punished severely. A good example would be selling the kids ps5 to pay for the glasses and not getting him another console this year and making him spend his free time doing unpleasant chores for a month with no outings or rewards of any kind.

This is both non-violent, moral, memorable, directly exemplifies the direct connection between wrongdoing and restitution. It doesn't assign blame to a condition as if being hungry forced him to punch his teacher in the face.

I suppose the reply could have been clipped, but there is no mention of a low blood sugar problem, no mention of a sorry l, just ‘little Timmy needs a super power not to be a violent prick’.

A reasonable place to start is teaching your kid that hitting people is wrong, remember teachers are people too, underpaid overworked people.