So today I was doing SFO-LAX-Tucson on UA and the LAX-Tucson leg got canceled. They protected elites on an American Eagle flight two hours later -- there was an advantage to being elite, and although it took a longish walk (from T8 to T5) and two shuttle rides (from T5 to T4 and then T4 to American Eagle), we got there without having to leave airside. Might have even worked to go from T5 to American Eagle had we thought to ask.

I see this is documented above, but I didn't have decent internet access to look through FT and didn't know, I was just determined not to leave airside unless it was absolutely necessary.

I did ask an airport cop, a United agent, and two TSA people along the way and they all denied it could be done. So much for local knowledge!