Continuity mistake: When Nixon and Winters are discussing being sent back home, the shaving foam by Winters' left ear keeps changing in size. (00:22:14)
Revealing mistake: In "The Breaking Point," Lipton is narrating the bombardment of the woods right outside of Foy. Just before he says, "What I saw that day," at 30:55, you see a section of a tree explode, but when the debris (i.e. the splinters of wood and snow) clears you see that the "blown up" section of the tree is unharmed. (00:30:55)
Factual error: The "officer on horseback" shot by Cpl Hoobler has a shoulder board denoting a Wehrmacht Sergeant's rank, but a collar patch denoting an SS Over and an SS Obersturmfuhrer (lieutenant).
Answer: That actually is the clip. It is loaded into the top of the rifle, and is ejected with the last round. See http://www.wwiitech.net/main/usa/weapons/m1/.
J I Cohen