Well… I wouldn’t call the following making my own ruling, but rather trying to lobby for a favorable, strategic one. This happened to me at Pinburgh this year:
Playing Twilight Zone in the backup bank, two balls in the lock, and I shoot the hitchhiker loop. Ball gets jammed up in there somewhere, and in the process of waiting for help, the two balls in the lock chase out and then the hitchhiker ball also magically releases itself. I trap them all up, one on the left, two on the right. When the TD arrives, I explain what happened and also that I know I must drain down to one, but I ask if I can choose which one to keep. After some thought, the decision was yes. I opted for the one on the left flipper as the options on what to shoot for are better.
Later in the same game I had exactly the same situation, but this time it was the powerball that airballed and got jammed up on top of a pop bumper. Lost one of the chased balls but managed to trap the other on the right flipper. Same decision - I get to choose which ball to keep. Of course I chose the powerball.
Both of those were calculated decisions on what I wanted to have happen during a ruling. I believe I was told there was no codified response to that specific situation, and it would be brought up for possible clarification at future Pinburghs.