Atlantis gave him the time to have character growth and become a better person. I like the way he reverts as soon as he’s in the same room as Carter before she gets there full time.
I thought he was going to sonic the mine and get on with the episode, but when I realised where things were going, the answer is simple - the sonic was in his pocket, but he couldn’t move to get it (or get Ruby to retrieve it) because that would shift his weight too much and set the mine off.