This was a technical exam, done remotely via Zoom. I had remote control over the interviewer's computer. Before the interview, I was told I could use any tool to solve the problems. However, in the interview, I was instructed to use a specific tool I had no knowledge of, because the interviewer had issues with their computer so other tools did not work, and fixing them would take too long. I asked if this was a tool they work with day-to-day and they replied no. The interviewer was keen to help me navigate this tool, but it took precious time from the interview. This was a frustrating experience as I wasn't ready for this, and made it feel as if the interviewer was not prepared for the interview.