If any part of Les's donation were to find its way into Deke's pockets, I'm sure the NBA would take a very dim view of the arrangement. But if Les were to donate directly to the hospital, Deke would not personally benefit, other than from some warm fuzzy feelings. I see no moral or legal objection, do you?
In this case, I am pretty sure there is little to nothing the NBA can do about that. The only way David Stern and his boys can come screaming is if it is done poorly like Glen Taylor (TWolves owner) and Smith did theirs that cost them those first round picks. I am glad Deke is back.