She may have scared herself. Or caught a toe nail... Did she scream for long, or just a quick yelp? My dogs dog 10 years yelps when you touch her, if she doesn't see you! lol She sounds like you kicked her...
Sometimes a scare is "self-correcting", for jumping, my big boy won't come down the stairs, cuz I never let him when he was smaller.I haven't had much luch teaching the older dogs, that I don't want them jumping up or down though! Still a work in progress...