Well first off, he didn't have a territory and was in a new surrounding is usually the main reason for his lack of aggression. Secondly was this a male or female? Males tend to be more aggressive. Thirdly how big is the tank?
its a 35, they are all small right now and I'm getting rid of the GT some how and puting the con and jag in a 75 as soon as i get it up. and there will be jag proof caves in it