This suggests the Vans pilot followed correct procedure - taking off he'd turn left at ~500 ft in a climbing turn to continue to circuit height where he could leave (or rejoin the circuit).
Not sure I would turn left at 500ft regardless of whether this puts me underneath crosswind traffic.
Surely, departing traffic should fly on the runway heading, over the numbers,
and then a bit further, so it can then continue its climb on an easterly or westerly track without the risk of hitting crosswind traffic from underneath. In such a conflict, neither would see the other.
Fair point about situational awareness by listening to the radio but this is of limited value because
- a lot of pilots misreport their location
- a lot of pilots don't report their location
- often one cannot make a report if somebody is making a long call
- some pilots lie about their position (report a position more advanced than their actual one) to get a clearance to a particular join
Personally, I fly a long way out over the sea, on roughly the runway heading, before climbing anywhere near circuit height.