Ragnar kills the same man twice. First with bow and arrow, later by throwing his axe.
The fjord backdrop is clearly missing in several shots.
Rollo tells Earl Haraldson not to send his "thugs" after him. Leading dictionaries trace the origins of this word (derived from Hindi "thag") to the first half of the 19th century, making its use in ca. 800 AD Scandinavia highly anachronistic.