any things possible but i highly doubt that the catfish did it what exactly do you mean ? how does it swim that is worrying you ? and for the not eating thats pretty normal and very very common for new eels all most all of the spiny eels i've had have gone on many hunger strikes
Try giveing it some time and make sure the waters clean do a few good water changes and just give him time to settle in
Try feeding it Blood worms, earth worms, red wigglers, brine shrimp, mysis shrimp, krill, and regular shrimp the kind people eat