I took a look at an 2002 Impreza with a 2.5 SOHC. The owner said the idler pulley had frozen and the timing belt broke.

 

They have installed a new belt and pulleys and water pump. It seems to run fine, I did not have the time to do a compression check.

 

No Cell on.

 

Valves bent or they got luckey?

Must have been lucky. There's no 100% guarantee that valves will get bent when a TB goes, just a very very good chance. Lower engine speed increases the odds of survival.

Were they having some sort of driveability issue after the install?

Never heard of someone getting that lucky. Do they compression test to make sure. Pretty crazy if everything is fine.