Didn't think it needed further comment. It is the crux of the problem wouldn't you agree, how does one complete a bombing run with Deff Koptas given 12" is too short and under normal interpretation of the rules you can not use it if you turbo boosted.I note that you didn't seem to bother with the other point, though...
As I noted earlier, the guys at the GW store said do the bombing run in the Turbo Boost phase. But as we can see from the commentary, it is a point that needs mutual agreement before the game is started. If someone is not prepared to accept the solution may be for that game the Ork player discards the bomb and uses his 15 points on something else.
Of course tournaments would need clarification in the notes I think. That is one place where people get antsy about lists changing.