I'm not sure if this has anything to do with your questions, but as a young and scared first time mom in labor with my twins (and in a hospital operating room full of a zillion docs/nurses) I did not push out my second baby. I had an incredible unstoppable urge, and he was a feet-first breech, and one of his legs came out and everyone was screaming at me to PUSH! PUSH! PUSH! I remember thinking, "f that. I am not pushing. Stop yelling." I consciously did NOT push and yet my body pushed for me and he came out.
My twins were born 10 minutes apart and in retrospect had I pushed it probably would have been about 2 min. But I was scared (for a zillion reasons: I was about to become a single mom of twins; they had TTTS and I was concerned about their health; the urge to push was unbelievably strong and I hadn't expected it to be that strong, etc) so that's why I didn't want to push.
My twins were born 10 minutes apart and in retrospect had I pushed it probably would have been about 2 min. But I was scared (for a zillion reasons: I was about to become a single mom of twins; they had TTTS and I was concerned about their health; the urge to push was unbelievably strong and I hadn't expected it to be that strong, etc) so that's why I didn't want to push.