I agree with the others on here, who believe that no exhibition game can be the worst loss ever.
Worst loss that counted, that I ever attended, was Niagara in the Holiday Festival late 90s. I think we outrebounded them by about 20 or so, committed something like 10 less turnovers, went to the line double the amount of time they did, and lost by around 25 points because we couldn't buy a bucket, and they couldn't miss.
That was easily the worst shooting performance we ever had, regardless of what the actual percentage record is for us. FTR, I think last night's STA team was better then that year's Niagara team.