Husband wondering about nursing school failure/dropout rates

So I'm the husband of a hard-working nursing student who's been at it for the last 18 months at UNLV. All along my wife has done well and passed all of her classes. As a medical graduate myself I know that it can take long hours of studying and working to get by and I've been truly amazed and proud of how hard my wife has worked to get through her degree program.

So why am I here? Because I'm truly angry and frustrated by what has just happened and my wife is too upset even to talk to her family, let alone get on here and vent. Two days prior to her planned graduation, with family all arriving and plans all set, she was told that she has failed one of her courses, by the typical <1% (I believe that she needed a 75% in the class and she got a 74.2%). In all her other courses she has had A's. Reviewing the questions she remembered vividly it seemed like there was tremendous ambiguity to me...

What truly amazes me is that about 20% of her classmates had this happen. All of these students passed every class up to this point, and then two days prior to graduation they flunked out. This seems like cruel and unusual punishment.... You make people work their tails off for months and then fail them just days prior to graduation! Many of them have children counting on them for support (ie. single mothers) or were in financial hardship just to reach that point, or had long term relationships fall apart due to the hardship of nursing school. All that to fail 2 days prior to graduation. I just cannot believe the lack of compassion of the faculty. Surely it must be possible to "weed-out" those who shouldn't become nurses long before graduation rather than two days prior.... In my schooling it seemed to me that most of the failing occurred within the first few semesters rather than at the end. I suppose the nursing school wouldn't make the same kind of money on tuition that way however...

So what I am wondering is whether or not this is commonplace? Is this something unique to UNLV? Is this something that other people have experienced at this school or elsewhere? Does anyone think this is fair?

Thanks for any comments, thoughts, or anecdotes,

Confused husband