So they knew the date but not the time? That's strange. Even still the game ended at 6:30 so by the time you got to the restaurant and all of this happened it had to be after 7 so they would've been late anyway.
Yeah, it was right at around 7 and they were in the middle of saying goodbye to the others in their party so, they would have missed the first inning, but not much more. I'm sure it was one of those things where they grabbed the tix and planned to have dinner with friends heading up to the game. They saw Nats fans filing in and then realized something was up. Nothing for them to do but look at their tickets, shake their heads, and then sit back down and order another margarita.