[eluser]Unknown[/eluser]
I saw you haven't had a reply in days, so I figured I would at least offer up my opinion, and it is only my opinion.
I personally always use an if/else statement, especially when dealing with anything that could be construed as security. To rephrase, I never leave off the else. Several reasons for this:
1. I don't want to take the risk of somehow the if (without the else) being skipped over and my script continue to run at its own will.
2. Easier to read later on when you come back to edit your code.
3. It just seems logical to me. To me it's the equivalent of using a try/catch without the catch.
I'm not going to give a spill about it's best practice or dive into any concrete theory, but it's only six extra characters for a little extra peace at night when you lay your head down on your pillow.
Happy coding!