I didn't watch but heard the same thing. I wasn't surprised. Corbyn is quite good at this sort of stuff. I think it is factored into the polls that he represents himself well as a sort of magic grandpa character.
But he is a Marxist and has always been. Everyone here knows it.
Also, Boris is a poor performer in those sorts of conversations. We all know that too.
So I don't think it means that much. If anything, breakeven was a decent result for Boris.
From a policy perspective, Boris is straddling the middle ground from a British perspective. People usually win from that place.