The tanks actions it is possible to be reportable but I would not give them 15 minutes if they ran to the start of the dungeon and sat down. If I saw that, and they did not answer within 1-2 minutes, I would vote propose then. They had plenty of time to say something as they ran to the start.

Healer did nothing wrong, a GM will tell you that is what the penalty is for. I personally do not like such actions but that is how the GMs see things.