Okay, so I found out today (by way of a serendipitous typo) that the OOPS command is a thing in AutoCAD. 
It undoes the last ERASE, bypassing any other commands you typed between. 

Okay, so I found out today (by way of a serendipitous typo) that the OOPS command is a thing in AutoCAD.

It undoes the last ERASE, bypassing any other commands you typed between.