If you go into Cityfight without any template weapons, or some serious hand-to-hand ability (or a nice mix of both), what the hell can you expect?
You took advantage of the situation available to you, and by the sounds of it his list simply wasn't balanced enough to deal with it - a well balanced list in City Fight simply HAS to include a couple of template weapons.
While we're on it, my and a friend have been playing reguarly over the last few weeks - his Ulthwe strike force vs My Infantry Company, I spent all week coming up with a list designed specifically to remove his Ulthwe from the table, and he decided to show up at the last battle with his Iron Warriors instead.
Naturally, I got hammered... he knew what I was planning for, knew what I was expecting, and used that to slaughter me. It wasn't dishonest of him, because at no point did we agree what armies we were playing with, I just ASSUMED it'd be the same army as the last few weeks and I made an unbalanced list designed to take out his WWP attack force, I've since learned my lesson and my list next week will be much more balanced.
Interestingly enough we're playing Cityfight, which means I'll be dusting off my Orks, and you can be damned sure that the list I write will be balanced enough to deal with Eldar, Tau, Iron Warriors, IG, Space Marines and an Armoured Company... because I'll definetly be facing at least two of them.
Of course, if you could give us an idea what list the Space Marine Player was using against you, that'd be nice...