I'm just surprised that I've never seen a problem using it exactly as I've written it above, which I do with great regularity. The docs say that the calling signatures are

open FILEHANDLE, EXPR
[download]

and

open FILEHANDLE
[download]

My syntax falls into the first case, but what constitutes an "EXPR"? I've got a string, the || operator, then the die -- does that qualify as an EXPR? I'll have to poke around the docs some more.....

Oh. Playing around with the right and wrong way shows me that my "|| die" syntax fails without die-ing.