It's hidden on Apple's site, but a developer can ask for an expedited review. Bugs, upcoming marketing dates, conferences, etc... all are reasons that can get an app review expedited.
But Apple makes it clear that it's an exception. Last year we got our first expedite request approved but our second one denied because we had already used up our first. Both were for critical bugs.
And here's what really bugs me about Apple. We have had multiple expedite requests approved the last few months, so it's clear there is no hard fast rule. The lack of hard rules is what is so annoying. One (or many) submission pass and suddenly an update will get tripped up by some trivial item that has been there since the beginning.
I believe you are entitled to one expedited review per app per year. In my experience though, getting your update reviewed faster , buys you precious little (yes, even if you are fixing a bug)
