How odd that at this moment, the only person who is saying that Jesus is the Messiah is one of his enemies. Peter isn't because suddenly he sees how dangerous it is to be aligned with Jesus. Not even Jesus himself is doing so, but he seems to capitalize on the moment when the high priest brings it up. Could it be that Jesus was joining the high priest in confirming his identity, creating two witnesses in a similar way to the two witnesses who testified against him? Jewish law actually required this two-witness confirmation to establish something as fact, so maybe so!