Help me work through a block/charge scenario.

[Loudwhistle]

B1 slides in late under A1, hard contact occurs.

This is all I need to determine a block in this case, sounds like B1 took A1's landing or he didn't establish LGP which would result in a block as well. A1 is an airborn shooter if I'm picturing the play correctly in my mind. Yeah its going to be an ugly crash, but an easy call from an official's perspective based on what I mentioned. Of course a video like Clark posts would be the best so one could see the whole play, but that is probably not an option.