My greatest "Well that escalated quickly" story came from a grocery store I used to work at.
It started with an accident. And honest to god accident; someone tried to put a bottle of alcohol back on the shelf and didn't put it back as solidly as they had thought. A few seconds after the customer walked away, the bottle hits the floor and smashes.
Amid profuse apologies from the customer and my reassurances, I get the bucket and mop, prop up the "wet floor" stands, and start cleaning it up. Just an ordinary day in the life of retail.
The mistaken customer eventually moves on.
In comes the Escalator. Kind of like the Terminator, but instead of killing, she just escalates the situation past all reason.
She seems calm. She asks me for a bottle of alcohol, which I promptly pass her so she doesn't have to wade through the mess. It seems like a simple interaction, and hey, I was nice enough to hand her what she wanted instead of having her wait until later.
Suddenly, she goes fucking Bruce Lee on my bucket. I have no idea what the tipping force of those wheeled janitor mop buckets are when half full of water, but her strike was clearly past that, as it goes completely over and floods the aisle with filthy water and soaking my lower legs. My shoes are flooded. My pants are dripping, and my socks are swimming in the gray water.
As I'm staring at her in stunned blankness, not even having processed just what had happened to me, she gives me this vicious little smirk and parades out of the aisle like she won the Mega Millions lottery.
I just stare after her, stare at the floor covered in gray water and slowly roll the bucket upright again. What just happened? I don't... I can't.... uh.... huh?
Aaand then she's screaming.
Apparently my manager was passing by and got a full view of her little stunt and is, in not-so-polite terms, telling her to put her shit down and get the fuck out.
Eventually she leaves, and two other employees appear with mops, sent to assist by said manager. Between the three of us, we manage to clean up the monstrous mess.
I just get the bucket put away and turn around to see three very grim faced, and very large, cops staring me down. They want to have a little chat with me. Right. Now.
Manager to the rescue; he wants to know what the problem is. The cops don't have friendly faces for him either, and I'm just stuck in this half panicked hands-up, "don't shoot me I don't know what's going on but there are angry cops looking at me" position with wide eyes.
The story goes that I rudely refused to help a woman who had asked me to pass her something at the mess I was cleaning up. Apparently, I then grabbed her by the hair, and threw her into the janitor's bucket, sending them to the floor and causing her to bash her knees on the hard tile floor. Whereupon the manager blamed her for the incident and kicked her out without even checking to see if she was all right.
The manager and I are questioned separately and the security feed was watched. God BLESS the security paranoia of this place; there wasn't a single point during this whole debacle that I was out of range of some security camera or other. They got the whole story: from the accidental drop to my putting the bucket away. They apologized for the trouble, promised to bring the wrath of The Book on her head, and left.
Manager: "I don't know about you, but I could use a stiff drink. You want to go home? Don't worry, I'll make sure you get paid for the full time today if you do."
Given the circumstances, I was glad to accept his offer.