Man that sounds rough. But honestly I would have done the total opposite thing. You can't just guess when a CEO is waiting on the line. I would have told them straight up my tech failed and we need to reschedule for a real fix. Making a call without your tools is how bigger mistakes happen. What did you end up deciding to do?
My old Dell at the Denver office crashed mid-demo once. I totally agree with Miles, being honest about the tech failure is the only move. Trying to fake it just makes the whole situation way worse later on.