IMO, there is pretty much no reason NOT to make it take points. The delay thing would then be pointless.
Except I don't care if someone loses points or not, while I DO care if I get my kill or not. If someone's gonna explode it's because they know they can't get me, and while it IS one less prop that I have to kill, it's one that I already found and some of the time it's denying me a speed boost. If I have a 5 second window to kill them after I find them or something I'd much prefer that to them losing points.
As an aside, why not just say exploding mid round on red is an offense similar to griefing? I know everyone likes to hate on the SourceOP server but that's how it is over there and they don't seem to have problems with it. That way you don't need to mess with the code and an admin can deal with it should they be on the server. I don't think it happens often enough that an admin would have to be called every time.