That doesn’t look like any documented Freemason handshake I’ve seen. I agree it’s strange, but not undeniable proof.

Edit: the closest I could find to this on the internet was this: https://www.quora.com/How-do-you-perform-the-Gamma-Phi-Beta-secret-handshake

Not sure of the validity of this, but I could not find anything Freemasonry related

That doesn’t look like any documented Freemason handshake I’ve seen. I agree it’s strange, but not undeniable proof.