I'll post an update here instead of making a new thread:
I admit I panicked and misjudged its behaviour, the gar was apparently never injured and has been swimming fine ever since, I guess it just needed some time to settle in. He looks comfortable in the tank and gets along great with all the other fish. The problem is it's not eating at all.. so I'm coming to you all for some advice because I don't know what else to try at this point.
I feed everyday as normal, I rotate between: carnivore pellets, frozen clams, frozen shrimp, live earthworms, & mealworms. The gar has been in the tank 2 weeks now and not even once has it shown any interest in food let alone attempt to eat anything. I've shoved food in its face using feeding tongs and it just turns away... The other day I dropped some feeder guppies (which is something I don't really like to do often) and they were all gone before the gar even reacted, so I can't say if he was eventually going to attempt to eat some live feeder fish or not.
I don't know what else to do, it just won't eat. Going to try some frozen lake smelt tonight, but other than that I'm really out of options. Is this normal and what else should I try? I've had stubborn fish before but 2 weeks is a bit excessive I feel now. The gar otherwise looks and behaves totally fine, quite active actually, pushing 9"