I had a Mom accuse me of nearly killing her daughter.
It was a super-hot day (100+) so XC practice was jogging about 300m from our meeting place to shady area, a body circuit with longer recoveries that normal, and then strides for the varsity kids - so 15-20 minutes total.
This girl did the 300m jog near the back of the group, and then stood in the deep shade with her water while the others did the circuit. This was normal for her, because she had "a unique deformity" in her wrists that prevented her from doing any exercise that put weight on her arms. She showed no signs of distress, never complained of any problems, and happily walked home with here friends after our 15 minute practice of which she did 3 minutes of activity.
The next day her Mom accosted me, stated she had suffered "heat stroke" at practice, and outlined her plan to protest to the principle and possibly to report my "callus neglect" to the police.
I told her that I was sorry to hear that she felt unwell, but that she had only jogged 300m, showed no signs of distress, never complained of any problems, and happily walked home with her friends.
(For some context, this girl's Dad had complained at our season opening parents meeting that our training was far to rigorous, and that it left the kids too exhausted to complete their homework. She was on about 15 miles a week, with lane 8 tempo at her own pace once a week)
The Mom's response was to repeat her accusations, with an increasingly intense tone, and I replied as I had above.
After about three or four more times of this, I had to excuse myself and return to practice.
She did report me to the AD, who gave her a serious meeting and told her he had addressed her concerns with me and that I would give greater attention to heat issues in the future. I was never questioned by the police, so I don't know if she followed through there.
Oh, and I had a set of parents threaten to sue me and the school if their daughter was placed on the 4x400 relay. (She was a 100, 200 sprinter). Both parents had been collegiate track athletes, and the Dad had run the 400 hurdles as his primary, but asking their daughter to run a relay leg was "endangering her".