Yes, it was an accident. Fleet was making a call regarding his mom's medicine. He didn't know the number, so he called the number for information 411. Instead of dialing 411, he dialed 911 instead. When 911 answered, he was probably like "Oops! That's not what I want!" and quickly hung up. 911 is going to respond because they don't know what's going on at the other end. Let's see... Maybe one was in the bathroom and the other, who is tending to some guests, says "Can someone get that, please?" Seems more logical for something to have happened after the party.