This reminds me of when I was at Honda school. We were paired up to disassemble and re-assemble 4 cyl engines. All we were given was hand tools. I had already done a bunch of those engines, so my partner and I were moving fairly fast.
When we finished we looked in the parts bucket, there was a clutch rod remaining. A tiny thing about 1/4 dia and 1 inch long. Small and easy to miss. My partner says, "Dang, we gotta undo the clutch cover again." "That will take 10 minutes with all those screws", I said. I unscrewed the oil fill cap (on the clutch cover) and dropped it in. He looked astonished. (I knew it was OK because those engines were never run, just disassembled week after week.)
Seconds later the instructor came walking by and picked up the bucket, expecting to find left over parts. We were 10 minutes ahead of everyone else in the class. He looked at us funny, then he looked around the bench top and in the drawer. When he didn't see any hidden parts he begrudgingly congratulated us. As he turned and walked away, my partner gave me the "Whew. Almost caught !" look.