Anyone else notice that Billy (Helenas son) was in Sweeney Todd?

Ok so, I'm sure I'm not seeing things but in the song "By the Sea" When Lovett and Todd are sitting on the sand and theres Toby playing with a layang-layang and a kid playing in the sand with a nanny? Well I was wondering if that was Billy?
I've paused this film a million times trying to pause it at the exact point that he's on screen and it really does look like him but I just wanted some clarity on this. Just so I know that I'm not going mad. Thanks :)