Um... you do know that phones are supposed to be resilient because *gasp* they will be carried and used in extremely harsh environments most of the time? My BlackBerries have survived countless falls, at least 4 super-soaking storms; my current one survived Monday's storm that flooded my freaking shoes as I was caught mid-commute on my motorbike. Any phone that can't handle that kind of beating is not fit for purpose. Phones that break if you look at them cross-eyed aren't fit for purpose.
Oh, and if you're a software developer, you should know that this also applies to software. Programs should not crash if someone inputs 1025 chars in a 1024 char field, if a network connection is broken/lost mid-transfer, of you get weird input, among other things. All exceptions should be handled safely. Your reservation system shouldn't break because someone inputted 2014-09-32.