Foul in MSC Octo-Finals 4, Questionable Call

[Kartoffee]

https://youtu.be/AsML6nmX-sA

This is a video of our alliance in the Octo-Finals at the Michigan District Championship. (Skip to 1:38) The ref at the close right station calls a foul on us, 2834, as we try to exit the courtyard in position 5. We didn't enter the secret passage, and they actually were close to a foul themselves, but there was still a foul on us. It wouldn't have been a decider for the tournament, but we have no idea why it was called. Can anybody explain? Is there a rule our entire team has overlooked? Is this just a bad call? (Heck we have had worse calls, like completely missing a defense cross that actually cost us a game).