Sorry to hear Liv. I have to say that regurge is the most disgusting thing to deal with. I have a pretty strong stomach but I've had two snakes regurge and I was no match for it.. One was an XL rat after 4-5 days, so I feel for you.. uugghhhh!!
It is weird to me, too, that the rat wasn't partially digested. Not sure I could guess as to why that is.
As for reasons for the regurge, the first two that would come to mind would be temp problems and stress from the Lysol, both of which were mentioned. Another potential problem might be if you are feeding F/T and the rat was not completely thawed.
On a positive note, Max has regurged once in the 2 1/2 yrs I've had him and (THANKFULLY) it hasn't happened again since. I know that it is scary as hell when it happens though. Remember to follow people's advice about waiting at LEAST 2 weeks before you attempt to feed him again and go with a rat one size smaller than usual... Best of luck!! And keep us posted!
Patty Crooker