Both the doors in the cabin of the van turned out to be locked, however, and worse, both the driver's and passenger's seats had a man in each, waiting on standby for the other agents to finish up. The driver even gave a worrying look to Biff from behind the window, but made no move to exit. The man in the passenger side had a cup of coffee in one hand and was scrolling through news on his phone with the other; he couldn't be bothered at all, plainly.
"So, that didn't work." Biff wondered aloud. But suddenly a devious idea came to him, with a devilish grin. What sorts of thing would a van need insurance for?
He rushed inside yet again, past the robotic men quickly and efficiently clearing it of any trace of his family. They looked like they may be finishing soon; Gotta hurry, he thought.
Heading into the kitchen, Biff grabbed the sharpest, sturdiest knife he could find, and then rushed back outside. "Let's see how you react to this," he said to nobody, just before slashing into the tire on the passenger-side rear wheel.