What should I do if someone was carrying my baby and slipped on ice?

And what happened? The effect on your baby should be obvious.Did s/he hit something hard (street), soft (snow)get hurt?Did s/he cry right away or not or get knocked out. If out, how long?Vomiting?Obvious injuries?Was the person horseing around and acting stupid (cps call)?Your question raises lots of questions.If baby is acting fine & playful & never vomited, baby may be fine otherwise baby may need a dr visit.
Possible injury. If there is a chance your baby was hurt then best go to the emergency room to have the baby examined.