1. It also produced a lot of tar. This tar is not seen in the geologic column anywhere on the Earth.
2. For their experiment to work, other byproducts of the experiment had to be removed at frequent intervals.
The meteorite experiment is interesting in and of itself because it shows that ammonia was present in the universe before or during the Earth's formation.
Unless you count petroleum.
I guess Tom has never heard of the tar sands in Kansas or the tar sands in Alberta, great sources for petroleum. Tar is nothing more than higer molecular weight petroleum, so of course it's found uin the geologic column. Production from tar sands, depending on how you define "tar", accounts for about 8% of the world's oil production