She thinks so too. She's known from the start that he used Mr Mayer as one of however many models for his accent.

"He didn't know me," she says thoughtfully. "I didn't think to ask about Cal, I really should have - maybe he and his Tony never came to Sunnydale?"

There isn't just one difference between their realities, necessarily, but that could potentially be a very big one.

Never mind that it's entirely reasonable that it never occurred to her, she still wishes she'd asked.