CIM
Sounds like you did exactly the right thing to me. Very strange, though. And did you ever find out what the "garbel garbel" was?
FNG
If the controller thought there was insufficient spacing, surely he'd have told CIM to go around?
F3G
You said "Only ATC can give landing clearances. A/G and AFISO can give information only." I agree. However, if an A/G or AFISO advises me not to land, although I have no legal duty to do as they say, I would still go around (unless I felt it wasn't safe to do so, which would be very unusual). Maybe they've seen something that I haven't?
(Incidentally, I've only seen this happen once. The fire crew at the airfield became temporarilly unavailable. An airfield can't be licensed without fire cover, therefore they were now temporarilly unlicensed. Solo student was on short final. It's illegal for a solo student to land at an un-licensed airfield, so A/G operator "suggested" that solo student might like to go around. By the time the next circuit was completed, airfield was licensed again. Not at all relevant to CIM's question, but just one example of when the A/G operator may have information which you don't have, and why it's a good idea to listen to him/her even though you don't legally have to.)