yes, why was this task extended? and why is it so quiet now from the police, the customer? they were on a observation task, non urgent - at that time..
perhaps something was developing, not untypical on a Friday night, and the crew wanted to go back to base, refuel and get airborne asap again. Or the next crew was waiting to take over? Old instincts to get back to base, or as close as possible? Bear in mind he was convinced he had enough fuel to get home - and indeed, he had. But not the engines. Could it be some medical issues affected the pilots performance, something he was maybe not at all aware off and caught by surprise during flight - so in such a case perhaps he felt not comfortable to land in a field or city at night and the decision to return to base was simply HIS best option at the time? who knows.