I think OHJ proponents forget that the OHJ ends up with a crosswind join, which takes us back to square one.
In an ATC scenario, when you are cleared to exit the OHJ, that is equivalent to being cleared to fly a crosswind join. Same risks, except you were subjected to additional risks while performing the OHJ earlier on as well.
Anyway, they will get the GPS log from the DA40 (the engine data logger logs lat/long as well) and find out exactly where it happened. A pity we are not going to hear about it for a year or so.