Slitherine

So at some point the game was changed so that units do not defensive fire on disrupted ennemy tanks

This was presumably done to avoid having disrupted tanks "absorb" defensive fire

However this creates a new problem.... Disrupted tanks are now able to safely run away to fight another day without being shot at... So for example if you have cleverly encircled a disrupted ennemy tank to finish him off, he is able to coolly drive past however many tanks you got (who presumably wave him on sportsmanlike).

Another trick is to drive the disrupted unvulnerable tank right behind a target , then rally it, and shoot the target in the back

This of course is not right.... I feel that the fix is to lower the probably of shots at a disrupted tank but still have it higher than zero

It sounds like you are referring to a change from the v2.1.0 update. This did not completely remove the possibility of reaction fire against suppressed armour, but does stop units from taking reaction shots with a low probability of destroying suppressed armoured targets, particularly when the shooter is running out of available reaction shots for the turn.

Keep in mind that there are a number of factors affecting reaction probability, for example most tanks have little or no chance of taking a reaction shot against a unit behind them.

hmmmm..... so far I have never seen a disrupted tank be shot at since that change took effect......

on the other hand what I have seen is shots galore at german tanks when the probability of killing them is 0% (e.g. shermans firing at close to maximum range at the front of a Panther)..... When I checked during my turn these same trigger happy tanks had 0% total chance againts that same tank at the same range