NPM quesitons on the SAM exam?

I just took my exam and failed it. I was completely prepared for SAM related activities as that is what i have been doing in my day to day work duties for a year now. HOWEVER why would i be asked 6-10 NPM related questions. i had no clue on them and almost 100% chance got all of them wrong. On the exam Study list it make NO mention of NPM. so i figured i wouldn't have to read into OTHER PRODUCTS when i'm taking an exam on Server and Application Monitoring. 

When i got to the results page it showed half categories for NPM and half of SAM. WHY WASN'T this listed on the Exam page. This felt like a freaking bait and switch, as well as a waste of 200$ USD. can someone please explain why SolarWinds wouldn't include a blurb saying.... "Hey by the way, you need to know NPM as well to take the SAM Cert."