I would say one cannot bomb on the first turn arrived, or on the first turn back after disengaging. The key for me is "Leave a marker in the original position of the flyer and then move the flyer as normal... Draw an imaginary line between the marker and the flyer's final position. This is the flyer's bombing run corridor."
If the bomber wasn't on the board the previous turn, there wouldn't be an "original position."
I vaguely recall someone defining an entry point on the table edge, then a stop point anywhere on the table, and using the line between as a bombing run corridor. This would pass a common sense test, but doesn't sound very much like the rules as written.
I would read it as you originally did, no bombing on the first turn back. I don't feel the point as beyond arguing, though.
