Continuity mistake: When R2-D2 closes the door to the platform in the back of the monastery (before Asajj attacks Ahsoka), Asajj stabs both of her lightsabers through the door, a few inches apart from each other, and starts moving them downward. In the next shot, on the other side of the door, there is already a solid line (the top of the circle) cut into the door. There wasn't enough time for her to have stopped and connected the space between the two holes. (00:45:40)
Revealing mistake: When Anakin, Ahsoka, and the clones begin their ascent to the monastery on planet Teth, the ascension cable of one clone trooper (second from the front when the shot begins) is not animated correctly and a gap can be seen between the end of the cable and the clone's blaster. (00:35:35)
Answer: Both Jedi Knights and Jedi Masters can have Padawans apprenticed to them; the rank of Master is generally awarded once their first Padawan has successfully passed the trials and become a Knight themselves. While Ahsoka calls Anakin Master in formal circumstances, that's merely an indication of her status as his apprentice; Ahsoka being only his first Padawan, Anakin is still only a Jedi Knight.
Tailkinker ★