I pulled Dan Croswell's
Beetle off the shelf for a quick look. It's discussed on pages 737-740. The primary sources seem to be an interview conducted with Walter Beedle Smith by historian Forrest C. Pogue, and a supporting ETO headquarters document, a letter written by Smith reprimanding Lee for the incident. Eisenhower apparently issued a directive to Lee, instructing him to avoid moving his headquarters to Paris, but the move had already begun and Lee judged it impractical to reverse. This was undoubtedly correct, and there was really no other place to site his headquarters. However, the problem was that Lee didn't bother conferring with Ike or anyone else (like Chief of Staff Smith) about the necessity to revise or revoke his order. He simply went ahead and completed the move, making Eisenhower look kind of stupid, because the latter had promised the French to keep US troops out of Paris. Lee was, apparently, admonished by Smith, but kept his job. The incident reflects poorly on both Eisenhower and Lee. Ike gave a fairly off the cuff order without prior consultation with his staff, and Lee apparently didn't see the need to communicate with his boss about his impractical orders. That's no way to run a railroad!