I didn't think I did anything like that, after the first time it slipped/slug-shifted, I made a point to keep the throttle steady and just listened.
But, given that someone else at least experienced it...I'll give it a bit...maybe it'll shake itself out...
It's supposed to be cold tomorrow too, looks like I have a reason to get up early instead of sleeping in...just to drive my truck and see if it does it again...(though it could do it after work today too, since it's not supposed to get much warmer)