I think you may be trying to join a server that has the command sv_lan 1 set.
This means that only computers on their local network (not the internet) can join the game.
Best thing to do is to try another server
Realistically, he could have any problem using a "cracked" version of Steam. If he actually is using such a copy of Steam he'd be better off buying a legit copy of Half-Life, but why would you just automatically assume that he isn't?
That aside, he hasn't responded for quite awhile now. I'd assume he has either solved the problem and moved on, or... gave up and moved on.