Factual error: Mel Gibson sits around the campfire at the railway camp with the lads, reading newspaper reports of the April 25, 1915 landing at Gallipoli. The 3rd Light Horse Brigade (including the 10th Light Horse Regiment from Western Australia) landed at Gallipoli on 20 May 1915. This would have given him less than 3 weeks to enlist, train, travel to Egypt by ship and land on the Peninsula. A bit of a stretch. In reality, the 10 Light Horse regiment was raised in October 1914, with the 1st-3rd reinforcements departing Fremantle February 19-22, 1915.
Factual error: In the final football game scenes ( from about three-quarters of the way through the film or so) all the spectators are wearing 1970's clothes and have 1970's hairstyles.
Factual error: In the boat-stealing scene, when the machine gunner fires a burst of blanks out of the M60 at the Cajuns, the weapon functions perfectly. However, the muzzle is bare. When firing with blanks, weapons have to have metal pieces called blank adaptors screwed into the muzzle to keep enough gas inside the weapon to cycle the bolt. Without one, the M60 would fire one round and stop.