What time of day was the programming the same?
Just comparing KBTX-3.2's schedule to KTXH 20.1's, I see they both run Family Feud from Noon-1PM. Some of the commercials would be the same in the same episode of a syndicated program.
At first glance, I don't see any other cases where their programming is the same, so there would have to be some other explanation.