as a mother my first instinct would be, like yours, to go through hell or high water to get to my baby... and for mothers of small children out there.. it never changes!!! My Babies are old enough to be on GE18!
It is incredibly hard to wait for the stars to align to be able to get to your child.. i have been there, but you were right to wait for the next call.
Your son's ADHD makes his routine important, BUT these were extrodinary circumstances to say teh least. Your need to see, feel, hear, smell your son is perfectly reasonable.
I would say though.. the receptionist sounds like she is or was in pure shock.. going by the rule book, clinging to it as though it was her lifeline. She is most proberbly sitting at home kicking herself thinking you idiot!! Of Course Ms X needed her boy... but don't expect her to admit that.. few do. The snotty was most probably a pure defence mechanism on her part, due to the stress and horror of the day.
As for feeling like a child... i still do when getting scolded... and those who work in schools tend to have that tone which makes us all feel about five.
I think you were right to collect for you.... your son, like most children, would most probably been quite happy to finish off the school day, then tell you all about the adventure, but your needs are just as important. A fact that is easily overlooked as you raise children to adulthood.
Thank you for your kind words, Mama V. You always help me feel better. <3