It was a shock to me too, especially as i had had them both on my knee earlier in the evening. not sure what the rescue will think though, they probably think he is here for life, and it might still happen if he settles down, but I can't risk Sam's health, 300g is a lot to lose in a month, and i can't afford for him to lose the same again next month - luckily he was at his heaviest all year last month, but even then he could have still gained some weight. Even putting him in with Ellie is still being confined, it is just a bit more space.
Trigger, i dont think that would work, as the others dont eat as quickly as him, so he would still be able to pinch food and they would continue to lose weight. I tried giving him extra last night but fed him before Sam - as soon as he heard me feeding Sam in the other room, he followed me, despite still having food in front of him.