Viola Moonlight
I'm Literally Just Here for WZCW
You're right there, absolutely no need to bring someone back if they aren't going to be used. I can't say I'm suprised though as Eugene got no entrance on RAW and did the job to the Miz, in a weird way it's almost as if they re-hired the man so they could fire him. But in all seriousness, it just doesn't make any sense (unless there is a valid reason, like Dinsmore failing another test but surely after his history he wouldn't even go there).
Actually, Nick Dunsmore was originally hired back to the WWE to become a trainer for the business. They only used the Eugene character for the one show so they could place an emphasis & more credibility in an unknown superstar to win a contract over someone who is very established. The Eugene release was most likely to rid of any rumors that he will be an active wrestler. They are still using him as a trainer apparently.