In the Dillard pic below the red arrow points out the space where the "red gates" are (slightly obscured by, what I assume is, the Stemmons sign).
We can't see the diamond pattern on the gates because they are wide open so it is just a black space.
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In the Allen pic below the same space is pointed out by a red arrow.
Again, we can't see the diamond pattern on the gates so they are wide open.
The difference in this pic is that the Hertz clock reads 12:40
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So we know the gates were open at 12:40
This means the film clip above with Sawyer and Brennan was definitely after 12:40 PM as the gates are closed.