ive got a bamboo shark (banded cat), with a maroon he doesnt touch him...ive asked my dads friend (lfs owner,marine biologist,etc.) he says u should be fine. just dont add a trigger, they tend to nip alot.
in my oppinion make sure ur buddys tank has sand and not a crushed coral or rocky bottum, it hurts the stomach of the shark.
also make sure there is alot of sandy bottom, like atleast a couple feet long and atleast 1ft and a half wide.
good luck
jake