All three of my lipos are damaged on that same corner of the pack. There is nothing in the battery tray that is hitting. It sits under the ESC (Rustler XVL 2WD).
15 things every LiPo battery user should know - The Drone Girl
How to Safely Dispose LiPo Batteries for FPV Drones - Oscar Liang
How to Protect LiPo Batteries from Crashes and Physical Damage - Oscar Liang
How to determine when a LiPo Battery is DEAD - RCexplained