QUIC as a solution to protocol ossification

I was at the talk, and yet he did hammer on and on about middle boxes. It sounded over the top until he said something along the lines of:

"The only fix is to encrypt everything. We had one byte, just one byte that wasn't encrypted. Then we when changed it, and we started getting reports of broken connections. It has only been out for a few months, and it wasn't published anywhere so no one could have known what that byte was. Yet ossification has set in."

At that point started to feel sorry for him.