But rather, they were insinuating hints - אלא דקמרמזי רמוזי
The (three) answers of the גמרא explain the ברייתא even if we maintain לייעודי גברא. Hinting to each other is sufficient evidence of collusion to make witnesses pay and maybe even to receive capital punishment.
Where they recognize the owner of the ox, etc. - במכירין בעל השור כולי
The answer of רבינא explains the ברייתא according to לייעודי תורא and לייעודי גברא. They cannot be coming to be מחייב him a ח"נ from the smallest of his herd, because he can say the animal that you testified about was lost. The ox becomes a מועד when they recognize him later. Nevertheless they cannot claim לחייבו ח"נ when we will recognize him, for then they should have testified after they recognized him; however they need to testify now to make him a מועד in order to warn the owner. A warning is valid only if the goring requires a payment.