i figure because: it's a late night show and it has a really specific listener base (a lot being made up of shawols) who know that he's pretty emotional, tbh. even casual listeners are aware because media reported on it before so he's pretty comfortable with being open with his emotions on it. but he doesn't cry often on there - like i can only think of maybe three times he's cried on air in all the time he's been on the show and it was either related to sentimentality or a tough topic. it was a spur of the moment thing and he really wasn't sobbing. it was more like it was obvious he was choked up but he kept it together pretty well considering that it's... him.