Witnesses are quoted as saying gunfire was coming from more than one direction.
Don’t put much stock in early theories or “eyewitness” accounts. Remember all the false leads on 9-11? How about the Beltway Sniper “white man in a white van” reports that led the police in wrong directions?
Here is how it often works. A group of terrified witnesses are chattering to each other post-danger, often many are chattering nearly hysterically at the same time. Many people will hear rifle shot echoes from different directions, leading them to believe in multiple shooters. Echoes are a fact of life with rifles, but how many civilian kids on that island had ever heard a real rifle fired around them or past them? None, I’ll bet. So every shot, sonic crack and echo is “another shooter.”
Then a witness in the group reports, “I saw another dark-haired guy over there with what looked like a gun.” (Could have been another island guest with a stick etc for self-defense in the general bedlam.)
Other witnesses hear him say that. When asked minutes or hours later about what they saw and heard, they report, “Well, some people saw another guy over there with a gun.”
It gets re-reported as, “Multiple witnesses saw another man with a gun.”
This is how the completely false, “white man in a white van” rumor got started. One fragmentary and incorrect report morphs into “multiple witnesses saw” nonsense.
You can just COUNT on it in cases like this.