I probably shouldn't even comment on anything that happens to the automatics since I don't have one. But the situation that "Defrostyman" mentioned really just sounded like the "traction control kicking in" to me.
One night an older Camaro "IROC" started to get frisky next to me, and I down shifted into 2nd. gear and started pulling away when I hit a rough section of road while under full throttle. Instantly (thanks to the momentary loss of traction) my RPM's dropped, and of course the Camaro drove right past me. I had my traction control turned off, but as we all know. Big brother is always looking out for us. That is, until we pull his fuse.