I’m not sure that fawn feel much fear since they’re supposed to lie in one spot and wait for their mother, a quick search turned up “Very young fawns do not appear to have any natural fear of predators, and may even walk up to humans” although I haven’t been able to conclusively verify the claim.
Can’t change the past, only decide what to do in the future. I agree that it should have been done straight away but perfect shouldn’t be the enemy of good, going back to check up on it is better than not doing anything.