to think that school should have mentioned that ds2 had a nosebleed

[cheeryface]

after getting a basketball in the face???

Depends how old he is I suppose. If he's too young to tell you himself, you could be worried if he has a further bleed, but I wouldn't have thought this is too serious.

I suppose if he hadnt had one before and was quite young then yes they should have told you,otherwise it is quite minor imo.

School should have mentioned it, but the teacher might simply have forgotten.

That's really poor! We get a note home very EVERY single accident. I often have a report that says dd hurt head whilst putting her coat on or dd hurt foot, falling over a step!