Hey man, I'm an pilot for the largest 737 outfit. You can guess which one and I'm a DE who gives many ATP checkrides to MIL guys. If what this DE said is true, that's pretty unprofessional. I certainly don't feel that way but what I will tell you is this. There is definitely a difference in performance between a Civilian and a Military guy. I know what you're about to say, 'well I only had 2-3 hours in the airplane'. All of the ATP flight schools for which I conduct checkrides offer Military pilots, or the general public for that matter, 4, 8 and 12 hour flight training syllabuses. Granted, you have to pay for that but it would be in your best interest to do so. The ATP is the only Part 61 ticket that does not require the endorsement for a checkride by a CFI. It requires the pilot to make his own decision as to his/her competency. Now if you were to fail, then you would require the endorsement of a CFI for retraining as per FAR 61.49. I have probably conducted 200 Military ATP's over the last 12 years and if I meet one more who says, 'well I only had 3 hours in the airplane' I will throw up. Pay for the additional time and show that to the examiner. He will not only appreciate that you did that, but I can almost promise you your checkride will be successful.