The Red Ribbon Army's appearance caught Yinsen somewhat off guard.
In the original story, when the Red Ribbon Army reached Korin Tower, Bora quickly defeated them. In the end, they tried to take Bora's son Upa hostage in exchange for the Dragon Ball in Bora's possession, only to be defeated by Goku, who happened to arrive at that moment.
Now that the Red Ribbon Army had appeared, where was Goku?
No one knew about Yinsen's doubts. Yamcha, who knew the Red Ribbon Army's reputation, was surprised they had shown up. Looking at the heavily armed soldiers around them, he seemed somewhat lacking in confidence.
Bora, however, did not take the Red Ribbon Army seriously. He efficiently killed those arrogant soldiers. Then, just like in the original story, their tiger-headed leader tried to seize Upa as a hostage in hopes of negotiating with Bora.
Unfortunately for him, Yinsen and the others were standing nearby this time. Since none of them had acted during the earlier battle, Tiger Head—Colonel Yellow, Major Yellow—had overlooked Yinsen's group.
Major Yellow's fatal mistake prevented him from taking Upa hostage. Yinsen dragged him straight out of the plane, knocked him unconscious with a casual punch, and tossed him to Bora.
"Thank you."
Bora casually finished off Major Yellow. As the guardian of the Sacred Land, he would not be polite to people like them. After dealing with the last enemy, he kindly dug a pit and buried them all rather than leaving their corpses exposed in the wilderness.
Only after finishing all that did Bora begin chatting with Yinsen.
"Are you Martial Artists here to challenge Korin Tower?"
"Yes."
"I've guarded this place for many years, but I've never seen anyone succeed in my lifetime. I hope you can do it."
Bora had challenged it once back