Talent is talent and in his case, at least it doesn't sound like he's a bad seed. The coach spoke highly of him and I'm assuming he was passing his courses. UCLA is a good school so it's not like he's some dummy.
If weight is his only issue, it's worth a shot imo. You could make the argument that Bryce Brown was a headcase between backing out on Miami, transferring from Tennessee and leaving Kansas State. He also had a handler and whatever other weird issues going on. Even NFL teams were hesitant and he fell to the 7th round. Did you see what he did the other night??
If Smith was into drugs, failing, committed a crime, has a horrible attitude etc. I could see passing on him but talent is talent and it sounds like he's a good kid with a poor work ethic. Maybe it's not that he has a poor work ethic, maybe it's just harder for him. It's not as easy for some people to give up food or go running all the time.
I'd at least look into him. Especially given the comments from Howland. He just lost what was once considered a prize recruit and after coming off a loss, I don't think he'd hold back on saying what he really thought if Smith was a bad kid. He was a good kid, it didn't work out and it was best for both parties to move on. Just like the right school could be the best for both parties.