I just pulled this from Wikipedia (which I'm not sure is the most reliable source):
The end of episode three states that Albert Blithe never recovered from the wounds he received in Normandy, and that he died in 1948. However, Albert Blithe did not die until 1967, after having two children, working for Westinghouse Electric, serving in the Korean War and achieving the rank of Master Sergeant. He was buried in Arlington National Cemetery with full military honors.
In preparation for Operation Market Garden, Sgt. "Bull" Randleman tells a new soldier to "drop your reserve chute — you won't need it — we'll be jumping low." This is incorrect for Market Garden, but had been correct for Normandy: on D-Day most troops jumped at 600 feet or less (200 m) — barely enough for the main chute to deploy. "The Market-Garden drop was a high drop, with average exits from 1,200 to 1,500 feet [370 to 460 m]."
At the beginning of Episode 9 it is stated that the date is April 11, 1945 and shows a scene with the company stationed in Thalem, Germany. At the end of the episode it finishes off the scene with Capt. Nixon announcing the death of Adolf Hitler. Hitler did not die until April 30, 1945. Also, the episode frames this after the company left Landsberg. The company was present at Landsberg from April 25 until April 30, and orders given in that same scene to advance on Berchtesgaden were not received until May 3.
Due to the miniseries only casting a limited portion of the Easy Company roster, certain roles had to be changed from their historical counterparts. For example, in the last patrol at Hagenau, the book cites Sergeant Mercier as the leading NCO with 2LT Jones as ranking officer. As Mercier was not cast in the miniseries, the position was filled by Staff Sergeant Martin (Dexter Fletcher).
The series states that Easy Company was the first unit into Berchtesgaden and the Eagle's Nest, capturing the town and surrounding area without incident. In fact, elements of the US 7th Infantry Regiment arrived a day earlier, and captured the town after minor skirmishes.
At the end of the final episode, "Points", it is stated that T/5. Joseph Liebgott became a San Francisco taxi driver after the war, but most accounts, including that of his son, state that Joseph Liebgott in fact became a barber after returning home from the war.
Technical Sergeant Don Malarkey was actually in a hospital, despite his attempts to be discharged to join the fighting. As a result, he did not participate in capturing Eagle's Nest.