In my work, when someone comes to me and assumes I or my team is screwing up because they “eliminated all possibilities at hand” 90% of the time, they screwed up and didn’t realize it.
Yeah, at that point the onus is on the person putting forth the problem to show their work. Start listing off possibilities that you've eliminated. You can have thirty years of technical experience and still be completely useless by assuming that you're just as smart as the person you're explaining the problem to.
"I did eliminate all the possibilities I had at hand"? Naw man, anyone dropping that line has only eliminated all possibilities that they can think of, and all of that supposed thinking about "all the possibilities" is worthless if they aren't going to offer it up as a starting point.