I was at a tournament last week, and the tournament provided hot dogs and hamburgers for a picnic lunch. A guy I knew was down there playing a match, and he narrowly won the first set. His opponent then ran off court and said he was going to go grab some of the lunch. The guy went and ate a burger, which took about ten minutes and came back. During the next set, he left DURING a game to take a bathroom break. I was pretty shocked and thought there must be a rule to address it. I told my friend he should just go report that the other player defaulted, but wasn't sure if that was how it worked. Anyone know?