I think it depends on who you are pitching to. The YC founders are from the startup culture themselves so I think that by itself allows them to recognize others

I think it depends on who you are pitching to. The YC founders are from the startup culture themselves so I think that by itself allows them to recognize others that have something on the ball, no formality necessary. When you're good you don't have to "act" smart; it will come across if you just be yourself, and I think that video illustrates that.