Murray is planning on going to the game with his colleague Vic, but then only he and Adam are at the game.
Veterans Stadium did not have troughs in the Men's rooms. They had urinals.
All Veterans Stadium sections were 3-digit numbers, with the first digit representing the "level" (1-7, for 100 to 700 level). Their seats appear to be on the 500-level, with the portal behind them being on the 600-level.
The exterior shots of Veterans Stadium are actually of the Los Angeles Memorial Coliseum. The style of the number above the staircase that Murray walks down to exit the stadium is very recognizable. (Veterans Stadium did not have etched numbers in this style.)
Beverly forces Murray to take Adam to the Phillies game because she doesn't want him staying home by himself, but Pops is over the house, so he could have easily kept an eye on Adam.