That's not a list, that's the binary comma operator. Any non-empty list is true. It may look like a list, but it's not one.

UPDATE:

Hmm, "Any non-empty list is true" was a dumb thing to say, as tye and tilly pointed out.

It reminds me of an MJD quote:

"If there is a giant purple water buffalo returned from a function, then $h = func() will always give you the length of its nose."

In other words, any non-empty list is true because you never have a list in boolean context.

However, I do stand by my first and third sentences in the original post. I think it's misleading to say if (1,0) or even if @array[0,2,1] is a list.

It is, obviously, a complicated topic.