Not quite. While the animations certainly could be better, they are harder to implent well in Fallout 3 compared to Mass Effect due the open nature of the game and the differences how the game world is handled by the game engines.
The Unreal 3 engine that Mass Effect use is a "special purpose" engine. The areas are all pre-calculated and optimized, nothing ever changes in them, etc. Whereas Fallout 3 is coded for the general case. Basically, Fallout 3 is sort of like Microsoft Word, and the master file is a document. The program has to handle the general case for everything -- terrain, buildings, statics, items, NPC's, animations etc. But a game like Mass Effect can have specific code to handle specific areas, they can optimize paths and collision to help with animations, etc.
For example, if the player stand on a slantwise ground in Mass Effect, the game will "know" that and adjust the legs accordingly. While Fallout 3 have to "guess" it and then try to adjust the legs accordingly. And the technical differences between "know" and "guess" are huge, and involve a
lot more manhours of work. Not impossible by any means though, but it's not a piece of cake.