Not really. You chase with a PIV at half health a T3476 with 1/4 of health. T76 fires and gets main gun destroy, PIV can't chase no longer and possible dies.
The problem is that suddenly tanks no longer have 640 HP rather than 480HP.
I wouldn't mind soft critical such as turret jam/lock, driver/gunner damage, etc. Main gun destroy is too binary on it's effect.
It can be even worse. P4 with 3/4 health brings a T34 down to 1/4 health and gives chase. T34 pens P4. P4 bounces or misses T34. T34 pens P4 again, triggering main gun crit.
Sometimes the stakes can go even higher. I've had one absurdly unlucky sequence of events. Diving his low health Panther with T34-85. After managing to rear-block him for the final shot, Panther + rak fired and brought T34-85 to main gun crit. T34-85 is destroyed and abandoned.
The swing was (490 + 185 fuel) + (380mp + 130 fuel) X 2.
The problem is that when you play this game thousands of times, a 5% chance of getting randomly fked over ends up being quite a lot of occurrences.