There's a 1:19 time stamp by the dispatcher. Allow up to a minute for error and work your way back from that time stamp and you have the Bowley report on the police radio taking place at 1:17.
Actually, there is a 1:18 time stamp as well.
a) “up to a minute” is arbitrary (there’s that word again)
b) you don’t just get to assume that the recording is continuous.
The recording isn't continuous.
Bowley made his call about a minute after the shooting and that wasn't at 1.17 (see my post # 682 on page 69)