It's not clear from your post whether this was at a bus/lobby call or whether you were wanting to gain access at some other time. If it was at a lobby call, when it's generally accepted that Neil is 'available' to whoever is there, I'd be very surprised, but in the latter case it wouldn't surprise me at all. In fact it's possible that your requests never got past security, either Diamondville's or the venue/hotel's.
Security and privacy issues have been discussed a number of times on this board, and IMHO a person is entitled to both whatever their 'celebrity' status. There's nothing I would have liked better than to get a word with him while he was here, but I knew it wasn't likely, so I wasn't exactly devastated when it didn't happen. Obviously I'd have gone to a lobby call like a shot given half a chance, but like many others I never found out where or when they were! I really don't know what I would have done if I had happened across him out and about somewhere, I think I would have been torn between grabbing the opportunity with both hands and thinking 'no, this isn't the time or the place'. (Yes, I know, this says more about me than about him - I used to be indecisive, but now I'm not so sure! )