i bet he placed the screwdriver in the pan and then flipped it and put it somewhere till engine assembly, and then when it was time to put the pan on he didnt bother looking under on the pan...and so there it is...

anyone could of done that.

Yah ive heard CLANK CLANK CLANK and saw a tools fly in my rearview mirror myself from leaving tools in the engine bay.

im just suprised the rods or crank didnt hit it