During the recent strength trail quest I used Time Stop multiple times on the boss level of the final stage. The attack counter for the boss heros would increase to either 4 or 5 but two turns later they world fire off a normal attack when their counters were at 3. These were normal attacks and not special attacks.
It appears (just a guess here) the logic for when they attack is firing at the multiple of their normal attack cycle. Form a programming point of view our looks like the logic does a MOD operation on the attack counter and if the result is zero it fires. Under normal conditions this is fine but if you take the counter higher than the start value it makes the attack fire when the counter is at zero and any multiple of the inital attack counter.
In any case the hero should not attack until the counter gets to zero and this is not what is happening.