I'd say it's a BIG YES for everyone (Dave is a horrible liar, Fletcher can't really lie because of the angel thing, Giles... doesn't enjoy lying, and Kenzie's just a teenager) EXCEPT Dani and Gilderoy.

Gilderoy is a really, really great liar and he's believed his own bullcrap for YEARS. But Sara can probably still tell when he's lying if she makes eye contact. Even though he's going to try to stop that.

Dani is the only one who Sara might have some real trouble with. She is an excellent liar and can pokerface from here to the moon and back. She was born and raised a liar and doesn't really have any "tells."