So take this 'totally hypothetical situation' and tell me what you would do. Let's pretend that your 13 year old son came home from ski club last night in 13 degree weather. And this same son told you that when they had arrived at the slopes earlier in the evening he found out his friend had forgotten a stocking cap, so he let his friend have his while he went without one for 4 hours of skiing. Would you:
Praise him for seeing a friend in need and meeting that need.
Punish him for being an idiot.
Mumble something under your breath in total confusion at the moral dilemma and kiss him goodnight.