I've only encountered two types of case failure; neck splits and case separations. The neck splits are due to work hardening of the brass and can be delayed by annealling the case necks. I've never seen or known of any gas release when a neck splits during firing. Just pitch them when you see them and pitch the lot when they start splitting in quantity.
Case separation is most common in belted cases as the cartridge head spaces on the belt so it is held in the chamber by the belt. You can check for this by looking for a frosted appearance circling the case just above the belt. It is caused by the case stretching towards the neck. Be most watchful for it if you have neck trimmed a few times. Good luck.