No shirts went flying.
However City Militia did fly out of their cities! I have experienced this at least two times now!
This is the first time it occured, during 1.3 while i was playing Scenario, war of anthys.
You see that army? Yeah it used to be even bigger but I managed to pull Relias out of there and more of the units but that was all that was obeying me, the rest of this milita chose Edmynn as their leader!

How did this happen you say? Well It was a combination of cluster screw up from the AI. Ceresa uh fallen enchantress herself hit my Fortress with winter spell then freeze spell, and Kraxis sent an army to murder the poor Pelleon hero who was forced to stand outside the fortress because it was already full with 9 units occupying it. Pelleon got punted into the fortress then Kraxis and Ceresa combo attack'd the fortress, I beat both of them back handily.
And my army got ejected from the fortress. I managed to pull few units out like Pelleon and Relias and few units. But that was all that could be pulled out. And City Milita refused to go back into the fortress even when i told them to.
I got fed up with it and decided to suicide them on purpose to make them die. So I can get my hero back.

Then I realized how ridiculously massive my army was. 18 Units lulz. So big to the point where the whole army couldn't attack and the extra four or five units got autokilled and the rest entered battle for the orgalsfield city.

I had way too much fun 
Then a town and four combined armies from Fallen enchantress and Kraxis, they got whittled down to this.

And I settled a village northwest of their current location, right next to that river ya see. And the militia army finally entered that village and my trapped heroes is freed again 
And 1-2 months later, in 1.4 ....
This happens again!

You see that City Milita army? He's moving up in world
From humble cannon fodder to general of army lolol.
How did this happen? Well, I was building an army for my naddia arena hero. And u see the dark fort the city militia is staring at now?
Well, two skeletons from there dark fort.. from turn 1 of the game. That fort used to be a desecerated cemetery, and grew to ash fields and finally became dark fort. I didn't intend to let it grow but I had no choice, i had my hands tied
It was a huge problem, eight undead armies patrolling around the fort lol.
Then one of the army from the dark fort which contained those 6 man skeleton units, just two of them attacked zanber fortress.. they got promptly flattened and the milita army is now out of the fortress. I tried to tell them to go back in, and left fortress and reentered. No Cigar.
They want blood, undead kind preferably the ones from the dark fort. it promptly squashed every single undead unit, even the dark sorcereror ran back into it's fort in fear. After the fort was razed and all undeads made dead again the militia army was finally willing to go back into the Fortress
I tried every turn and it refused to return until the undead got wiped out.
Yeah. My mind was fucked by that experience with zanber fortress today.