So now that the big show is is over....
This is what I have for the timing of the two "1:19" calls with respect to the Bowley transmission. If I arbitrarily assign the Bowley transmission at +0:00 minutes, then the first "1:19" comes in at +1:16 and he second one comes in at +1:56. The two 1:19 calls are 40 seconds apart. What we can get from this is that it's safe to assume that 1:19:30PM on the dispatchers clock occurred between the two 1:19 timestamps, since the interval between the two timestamps is greater than 30 seconds.
At this point, we consider two cases.
The first is that the first timestamp happened at 1:19:00PM . Then the second one would have occurred at 1:19:40. Therefore, 1:19:30PM would be 10 seconds before the second timestamp in this case. This is the upper limit for 1:19:30.
The second case puts the second timestamp at 1:19:59PM (and we'll round up one second to 1:20:00 just to make things look neater). In this case, the first timestamp would be at 1:19:20PM. In this case, 1:19:30 would be 10 seconds after the first timestamp.
Plugging this back into the Ch 1 recording run time, we get:
+0:00 Hello, police operator....
+1:16 1:19 #1
+1:26 Lower limit for 1:19:30PM
+1:46 Upper limit for 1:19:30PM
+1:56 1:19#2
It's probably better just to say that 1:19:30 occurs at +1:36 +/10 seconds after the beginning of the Bowley call. That would put 1:18:00PM at +0:06 +/- 0:10. Or, the Bowley transmission begins at 1:17:54PM +/- 10 seconds. It could be as early as 1:17:44 and as late as 1:18:04.
Having said that, I should add that Callaway hits the air at +2:12 after the beginning of Bowley's transmission. That would put the Callaway transmission at at 1:20:06PM again +/- 10 seconds.
Nice bit of speculation, based on the assumption (1) that the dispatcher clock is only marginally off, when it could in fact be two minutes off, not from real time but from the master clock in the dispatcher's office and (2) that the dispatcher made the calls on time.
Another problem is the fact that the official narrative has the time of the shooting between 1:14:30 and 1:15. Callaway's arrival on the scene, which happened during the 46 seconds between the end of Bowley's call and the arrival of the ambulance, makes it highly unlikely that Bowley started his call at 1:17 or even 1:17:44(or later).