Even then there should not be any alone time.
I coach BB and Softball and would not consider being alone with a kid but it did happen this fall. DD was sick on a practice day and I went to the gym. While turning on the lights the door opens and one of the girls comes in. I ask where's your mom or dad? Seems they were late picking up a sibling and dropped her off. I gave her a ball and sent her to shoot while I sat at the opposite end of the gym. I did speak to the girls father who has coached about not just dropping her off. He agreed, apologized and said it wouldn't happen again. I'm protective and suspicous and would question why a kid was alone with a coach in the gym. I would never call a kid on their phone but would call through a parent if something needed to be conveyed. This guy calling your daughter is creepy.