Around 29:16, when Private Eugene Sledge platoon arrived to the shore. The camera show a marine jumping off the side of the amphibious vehicle. Around 32:11, when Robert Leckie's platoon arrives with their own vehicle, Sledge's disembark scene is shown again.
(at around 30 mins) As the Marines are landing on the beach, there are a few Marines firing .30 cal machine guns mounted on the Amtraks. At one point, a gunner pulls the cocking handle of his weapon - in the shot, the cocking handle is on the left side of the weapon. The shot has been reversed, as a .30 cal with the handle on the left never existed.
Msgt is correctly referred to a "Gunny". A Marine Gunnery Sergeant has three stripes above and two below, which is the insignia of Msgt Basilone.
Throughout the mini-series, Elmo Haney is referred to as "Gunny". However, the rank insignia on his uniform is that of a Staff Sergeant.