Yea I think the mistakes can sometimes be our best asset while beatmaking.
I once had my SP-12 (not 1200; the original with the commodore 5 1/2" external drive!) hooked up via MIDI through my ASR-10 keyboard so I could use the pads on the SP-12 for the sounds on the ASR. So I had the ASR muted, and I was workin on using another drum line, to add SP-12 808's to the drums, but then I switched the ASR sound from drums to Rhodes, and turned it back up so I could play along with the drum line. The SP-12 was triggering some crazy ass sounds on the rhodes from the original drum pattern, and it sounded SICK. I was like "WHERE'S THIS SHIT COMIN FROM? WHO POSSESSED MY KEYBOARD?" (Back in 97 I wasn't as into procedures as I was just ready to hit a key or pad) But I made a sick ass beat that I sold the next day (also by mistake) for like $200.
And several times, it would happen where I would load the wrong patch on the same midi notes, and it would sound ridiculous and I'd use it, or layer it on top of the original sound.
Sometimes we have an outline in mind of what we want to start with, or what sounds we want to use, but when you open your beat later, fuck around with some different sounds and it can take you by surprise. Take your drum MIDI and select piano instead of drums and you may be surprised. 7/10 times it sounds dumb, but those other 3 times, you'll be like "Why didn't I think of that earlier?"