This is due to the indirect-object syntax, and is a more elaborate variation on [this example](https://stackoverflow.com/a/11695310/4653379).

The ["indirect object notation"](https://perldoc.perl.org/perlobj.html#Invoking-Class-Methods) allows code

     method Package @args;

     method { $invocant } @args;

to be used instead of

     Package->method(@args);

     $invocant->method(@args);

So the "try" and "catch" words don't matter.  The interesting bit here is the more involved and extended syntax, with two parts, each in this indirect object notation.

This means that

    try {
        call_a( 'x' );
    } catch {
        die "ACTUALLY die $_";
    };

is equivalent to

    (do {
        call_a( 'x' );
    })->try(
        do({
            die("ACTUALLY die $_");
        })->catch();
    );

which simplifies to

    call_a( 'x' )->try( die("ACTUALLY die $_")->catch() );

The code is interpreted with valid syntax (!) and it is the _contents of the block after `try` that runs first_ --- so the program dies and never gets to go for the "method" `try`.