> Not even to 911 as emergency calls are error prone : You said someone was attacked by a suv and knife when it was a pickup truck and machete, you go to jail

Very few states have anything resembling this specific federal statute, and one doesn't typically call 911 to obtain service from federal law enforcement agencies. And in the case of a 911 call specifically, "heat of the moment" and "good faith" do a lot of work.

Unless you obviously intended to mislead an emergency services response, you will not be criminally implicated from good faith statements made during a 911 call regarding some incident you merely observed as a bystander.