"Right in town?"
Yes
"In broad daylight?"
Yes
"If it was organized, why didn't any friendlys warn them before the arrived at the ambush point?"
Not too many friendlies in Fallujah. The men who were ambushed were civilians escorting a civilian truck convoy. This wasn't a military operation. That's not to say it wasn't professional. But many of the assets that support a military operation weren't supporting this one. The mob that burned the bodies of the Americans killed, was not a military target. Sorry, but that is a simple fact, and our military does not train its combatants to purposely violate the laws of armed conflict.
No need to apologize, but a source would be nice regarding this organized ambush.