Gosh, this code is really messy, and the wrong indentation really does not help. And, above all, when you use operators having almost the same precedence, you should use parentheses to clarify your intent.

I simplified your code to this (in a one-liner type of execution):

$ perl -e 'our $cookingcounter = 350883;
> our $garlicbreadheadstart = 600;
> our $ovenempty = 0;
>
> my $holdtime = 0;
> if (
>     !$ovenempty
>     || $test
>     && $holdtime = 1)
>   ) {
>     die sprintf "Main Dish or Appetizer Cooking: %d, hold for %d", $
+cookingcounter, $holdtime;
> }'
Main Dish or Appetizer Cooking: 350883, hold for 0 at -e line 11.
[download]

As you can see, $holdtime is not assigned to 1. The important point is the precedence between || and &&. && has a higher precedence than ||. So that the preceding code can be interpreted as:

our $cookingcounter = 350883;
our $garlicbreadheadstart = 600;
our $ovenempty = 0;

my $holdtime = 0;
if (
    !$ovenempty
    || ($test
    && $holdtime = 1)
  ) {
    die sprintf "Main Dish or Appetizer Cooking: %d, hold for %d", $co
+okingcounter, $holdtime;
}
[download]

In short, if !$ovenempty is true, none of the rest of the code is ever executed, because:

- !$ovenempty evaluates to true,

- and that's enough, we won't care about conditions grouped in a conditional having a lower priority.

So that the rest of the code is not even executed.