The Amtrak note above is probably the real reason, but yours is plausible! Semi-related, Prairie Home Companion over the weekend had a short skit with a member of the "Minnesoata Border Patrol" that was hilarious, and mentioned the game.
BTW, the PacNW Seismic Network folks monitor the stadium now, partly for fun and partly for research, after quakes were noted on a nearby seismograph during Seahawks games. Check out this blog [
pnsn.org] for fun and a report on yesterday's game.