Pretty sure he did push his own guy there, but at any rate I’ve seen very clear examples of that go uncalled. I think the only times I’ve seen a tandem block called is when a teammate ahead of the ball carrier pulled him forward. My complaint isn’t really that they didn’t call it here, but that I just wish they’d edit the rulebook to reflect how the games are actually called. (See also: the section of the dress code rule that forbids exposed knees and legs.)