A couple or so years ago the question was raised as to why US entrants to the Number 1 BFTS school in Terrell, Texas, had already received some flying training prior to entry.
The answer is provided by Tom Killebrew in his book " The Royal Air Force in Texas: Training British Pilots in Terrell during World War II. " at page 106.
The US Army had been previously critical of the standard of some of those selected by the Royal Air Force for training at the BFTS Schools in the USA. At a very senior level in the US Army it was decided that now that the boot was on the other foot, especial care had to be taken to ensure that only suitable US entrants were selected for training on these courses and therefore those being considered for selection had to have prior flying experience. On number 16 Course, one US entrant was a qualified commercial pilot and a second, a qualified instructor.