Well, Gary had some bad luck, yes...however, as I have been preaching for years: unless you are willing to pony up much more $ than what you pay for the amps for some specific AC units, go straight into the wall !!!!!!
While the amps are very well protected, shit still happens...so, if you're in a particularly iffy area weather wise, than you might want to play this one out according to your concerns...other than that, with such high current and fast designs such as ours, the wall is the way to go.....