The whole narrative of him taking to long to call the police is incorrect anyway. Because it implies that a call from WHF actually happened and the argument being the duration of time it took him to call the police is is suspicious. That's illogical because if the the call from Nevill happened it don't matter how long it took JB to call the police.
If the call from Nevil never happened. Then there was no reaction time. He created a time gap for no apparent reason. Because he could have made Nevill call happen when ever he wanted to say it happened. And the reason why would make no difference to the premise regardless.
That's a good point, however, before calling the police, he called Julie and he looked up the station number - those are the reasons for the time gap. Remember the initial time he gave for calling the police was much earlier than is being suggested here.
Of course he later realised that calling Julie first might sound odd, so he said he called her after - he also told me this (which I don't believe). Adding this to what the CT are claiming would extend the time even further.