While Peter Sagal was clearing up what a billion is in context to the first queston during Who's Bill This Time? to Maeve Higgins (due to the different definition of billion: thousand million vs. million million). During which, Peter referred to Maeve as British. Maeve is Irish.
The listener contestant for the Listener Limerick Challenge segment was also named Maeve Higgins.
Maeve answered "Twitter" for her first Lightning Fill-in-the-Blank question, to which Peter initially said "Yes" but almost immediately switched to "No". The correct answer was Tesla. For Maeve's second Lightning round question, she guessed "Kevin McGraw" and Peter said that he pretended that she said "Kevin McCarthy", which was the correct answer. Peter slipped out the answer while reading Maeve's fourth Lightning round question by saying "old..." instead of "blank-est".
Another instance in which the highest score is equal to the sum of the other two scores.