Were you possibly interviewing for a job in law enforcement or a job in some kind of high security area/field?

I have been to a couple of interview boards for law enforcement positions in the distant past, and that sounds like what you are describing.

For one department, I had passed all the written, background, physical fitness, physical agility, psychological, and polygraph tests. I actually max'ed out the written, physical fitness, physical agility and passed all others with flying colors. Then came the interview board....

Four hours in front of 12 officers plus the assistant chief. All the coffee or water I wanted to drink. No restroom breaks.

They did it to test my ability to handle stress, and think on my feet. I had these guys coming at me NON-STOP for 4 hours. I knew it was coming, made it through and still did not get hired. Found out later there was a quota to meet, and I did not fit the image and plumbing of said quota.