Two quick notes.

1) You didn't really drain the AAs if they were powering a cell phone. Most devices require a minimum voltage and turn off when you drop below it. As AA NiHMs start off at 1.2V, you're already at something of a minor disadvantage, and when your cell phone stopped working, the batteries weren't empty; they just couldn't power it anymore. The only real ways to fully drain a battery are to let it completely self-discharge over time or as part of reconditioning phase in a good charger. An unregulated flashlight will speed the process along, but I don't think even that will do it.

2) Yes, battery widths (and heights) can vary slightly. You think there would be an ANSI standard to prevent this, as it can be a problem in devices with very tight tolerances.