to jump in a little late...(and rambling...since I can't seem to form good sentences today...maybe because I have a lot to say here

sorry)
aA someone w/ ADHD who works in education, I do think I understand both sides.
In some ways, because of my personality, I do consider it something of a blessing I didn't have a diagnosis when I was a kid (I was diagnosed while in college, and ignored the diagnosis for the first few years out of pure cussedness) ...it kept me from being able to use it as a crutch. (of course, I had the blessing/curse of being raised by educators, so I had more coping mechanisms ready for me than your average kid).
I do take issue w/ some posters automatically saying it's a result of over diagnosis...I do see the problem of over-diagnosis in some of the schools I work in, (parents who doctor shop and ADHD as an excuse) but in other schools I work in (especially poorer schools and/or extremely rural or urban schools) there is still a lot of backlash against "over diagnosis" and kids who may have such a disorder are not diagnosed and (especially girls, anyone who has an "inattentive" rather than "hyperactive" form) are not sent for treatment because of the social stigma and the assumed implied accusation of bad parenting.
("what, someone is implying my child might have a LD? how dare you judge my kid/imply I'm a bad parent/try to brainwash us" is the reaction to the suggestion...)
(There is over-diagnosis, there is under diagnosis, an unfortunately if you read a lot of the research, the lines between the 2 extremes are often drawn along $ lines)
(and as far as all kids acting that way...of course it works that way. I can read the symptoms of clinical depression and say "yeah, I have some of these", because everyone has some of them...but since I have *some* of them to a very mild degree and they don't interfere w/ my life, chances are I don't have clinical depression.
Same goes for ADHD. If someone is mildly inattentive and that inattention is the only symptom, chances are, no, there is no ADHD. But that is far from the only criteria used for a diagnosis. And there is a difference between 'normal' childhood distractability and the inability to function in certain situations because of attention issues. If it interferes w/ normal life, chances are it's not just childhood distractability.)
I do see how it can be used as a crutch...In what can be a good or bad moment of substitute teaching years ago, I had a kid say "I can't sit down and do this, I have ADHD" and I floored the room with "so do I, you can do it, you just may have to do it differently or work harder". I might have lost some points w/ the school's principal, but I gained some w/ the kids...
Personally, understanding my ADHD did wonders for me.
I was able to develop and improve my coping mechanisms because I understood that some of my "quirks" were things I did for a reason, etc. I didn't/don't think I use the "it's not my fault I did X, I have ADHD" line; I do understand the uses of:
"I am more comfortable with X, and less comfortable with Y because of my ADHD, how can I use this to my advantage?"
"knowing that X is a challenge for the following (ADHD related) reasons....., how can I make sure that I succeed in X?"
My ADHD diagnosis allowed me to break the cycle of eating disorders that I had built up to regain control. My diagnosis, even without drug treatment (I don't medicate for various reasons I won't get into) helps me understand and exploit my strengths and compensate for my weaknesses.
I DO wish people who gave diagnosis would encourage people to sit through a run-down of what the disability (and I use that term loosely, ADHD can be empowering too :-) entails. Because if all that mom got was ""she has trouble paying attention and following directions." there are going to be bigger issues...because ADHD is NOT just a learning disability (any more than autism or blindness or schizophrenia could be considered purely a learning disability), it's a part of this kids life and it is not just about paying attention. In fact, if this child uses hyper-focus, it can be a problem of paying to much attention...
I know the OP isn't the person who deals w/ these things, but if it comes up again, could you gently point the parents to their local CHADD chapter? (
http://www.chadd.org/) some CHADD groups are better than others, but they can at least point them toward good resources.
(I would also highly, highly recommend Hallowell and Ratey's books the "driven to distraction" series)