When Riko sneezed while getting a haircut, was that by accident or did she do that on purpose?

Before the game against Rakuzan, Hyuga was giving Riko a haircut. And Hyuga was about to say something, but then Riko sneezed and said something.

Was that sneeze on purpose because she knew what Hyuga was going to say and wanted to stop him from saying it?

Or was that sneeze purely accidental?