Saint Patsy didn't purchase a movie ticket.
Postal's box office booth was flush with the storefronts.
Brewer saw Saint Patsy approach the theater and then disappear from view.
Had Saint Patsy stopped in front of the booth to purchase a ticket, Brewer would have been able to see the transaction.
Additionally, the box office only opened at 1:15 PM and Postal had sold a total of 14 tickets, mostly to patrons that were waiting for the office to open for the first show.
The cost of a ticket was 90 cents, so if Saint Patsy had purchased a ticket, he'd have to count out 90 cents or fork over a dollar and get his 10 cents change. A transaction Brewer would have undoubtedly noticed.
Tippit's murderer wasn't pausing to buy a ticket.