One that struck me on our building of a 25,000 s.f. commisary. The erection foreman called me and said the "frames aren't fitting right--they sort of lean to one side". I go to the job--the frames are all up and braced--sure enough it looked like it was leaning to one side! Digging into my vast store of knowledge, I deduced that one side of the rafter beams must be longer than the other--especially since the splich plates at the peak had a 2 inch gap at the bottom.
With the crew standing around, we debated who was going to shinny up the col. Hook a tape on the knee splice--shinny out to the peak and get a reading. One of the young recruits (brash-no good sense) settled it by VOLUNTEERING! He certainly was agile, went up that col. Like a tree climber with cleats, hooked the tape and crawled out to the peak--30 ft. above the concrete--held the tape to the splice--and silence-- I shout "what's it read?"--silence--A bit louder I say, "what the hell is the dimension?" another silence--then he spoke up--"Mr. Red, I don't know how to read no tape with all these numbers on it" !!!
Moral? Be sure you know what you're doing before you open thy mouth!