meself, what the Crow scout, Half Yellow Face, actually told Custer was: "You and I are going home today by a road we do not know." This was related by an interpreter who had left the column before the battle began.
As to the assertion by the OP that he natives were armed with repeating rifles while the cavalry had single loaded carbines, There is some truth to that. In the months leading up to the battle Sitting Bull's forces had managed to procure about 200 repeaters from gunrunners. This meant that approximately 1 in 10 warriors were armed with these "all-day guns". The rest were armed with muzzle-loaders, with some of the youngest warriors still using bows. The 7th Cavalry, like all troops in the west were armed with Springfield carbines. The government had judged them superior to the Henry and Spencer manufactured lever action repeaters. They had twice the range and stopping power as breech loaders and they were much faster to reload than muzzle loaders. Combine that with the fact that repeaters also had reloading downtime after a rapid burst and a well operated breechloader could actually maintain a higher rate of fire over the long term. It was also believed that repeaters would use up ammunition too fast.
   Did this possession of about 200 repeaters by Lakota fighters effect the outcome of the battle? Perhaps. Battlefield analysis long after the fact, based mostly on the recovery of spent ammo, has led to the speculation that a strategic use of these rifles at a crucial point of the battle may have turned one of Custer's flanks.
    This is as much as history has to say on the matter. As for my personal opinion, once Custer led his men to that point of no retreat, where his force was outnumbered 10 to 1, they were doomed. If Custer had accepted the offer of Gatlin guns at the beginning of the campaign and taken a more defensible position, it might have been a different outcome. He rejected the Gatlins because he thought they would slow him down on the trail. He didn't fight defensively because ha was relying on intelligence that the native force was much smaller than it was. Indian agents had provided the army with info that there were no more than 800 "hostiles" in the area, based on the number who had originally followed Sitting Bull off the reservation. They did not consider that in the weeks prior to the battle thousands more had unofficially left the reservation and joined force with Sitting Bull's band for the summer buffalo hunt.