Yes. But Bethesda was responsible for the Quality Assurance so they are responsible for errors.
This is true for the PC version, I know nothing of the PS3, but the final QA for
all 360 games is done by MS.
NV: If the game shows signs of slowing down then restart the game. I bought the game on UK release day and had maybe 3 or 4 crashes in 80ish hours, the only truly weird graphics bugs I've seen have been on the 'net, review sites, youtube etc.
Even if I have to save every hour, if a game has imaginative, intriguing and engaging content, it is a small price to pay.
Edit:
The poll is missing the option for 'I did not encounter any game breaking bugs in NV'