Another parent is threatening to sue us (the parents) and the center over my kid biting

I don’t know if I’m seeking advice or reassurance or what but I’m definitely freaking out a little right now.

Some backstory, my child “ (just freshly two when this began) started biting at daycare right after the new year out of nowhere. Like literally went from zero to a hundred, never did that kind of thing then suddenly was biting or attempting to bite multiple times a week. At first we were told it was normal/developmentally appropriate and they would work with him to redirect, but it didn’t seem to be getting any better and we were told other parents were getting angry and that one mentioned suing. To keep it from getting too long, I’ll just summarize by saying this whole thing has happened over about three months. It took about two months from the start of the behavior, but a combination of OT and strategies at daycare (we were already doing speech therapy when this started) nearly entirely stopped the behavior. In fact the teachers told us they saw multiple times when a bite would normally happen (our child getting pushed down, having their toy taken, etc) and they only reacted by getting a teacher.

Then earlier this week, nearly a month since the last bite, it happened again bad enough to break the skin on the other kid. Their parents have now withdrawn their child, and have said they’re going to sue the daycare, us, and report the daycare to licensing.

I’m a little bit sick over this. Has anybody been through something like this before? Did the person actually sue? Did anything come of it? Was there trouble with licensing? For what it’s worth, our center has been amazing and says they’re following their handbook which is based on licensing standards and thinks the other parent has no leg to stand on but that doesn’t mean the other parents won’t still try.