You can only win with a blunder. A 2700 player has such a great long-term memory understanding of patterns, positions, strategies, tactics, etc. that we, the club-level players, can't expect to compete.
I have relatives who are not highly educated who think that I, a chemist who completed graduate school at IIT, should have been a company CEO or have won a Nobel Prize because I amaze them by how well I understand finances, the stock market, and how quickly I call out the answers while we're watching "Jeopardy," etc.
But I know so many scientists that are brighter than me or understand business better than me because I'm at a high enough level to understand how truly amazing they are.
I think it's the same with chess. I certainly don't have the expertise to say why Fischer may have been better than Kasparov or vice-versa, so I can't say exactly why we club-level players don't have a chance against GMs. But having seen GM's win all the games in simultaneous matches, I know it seems to be true!
I would be interested in asking Daniel Rensch about the tournament personally, I don't know about you, but anyone who loses to Daniel Rensch must be pretty drunk! (jk)