The 1 && part is being optimized out of the statement.

this seems a rather dangerous and naive optimization to me, given that also this:

$x = 1 && $y = 2;
$x = 0 || $y = 2;
[download]

gets "optimized" as:

$x = $y = 2;
$x = $y = 2;
[download]

perhaps the p5p people should do something about it.