Marion

[GingaDensetsuAleu]

Why did Steward pick Marion to test the coin on?
It can't have been random, he knew his name, as we know because he asked to verify when they first met at Jessica's treehouse.
It potentially might have been because Marion habitually left his window open at night, and therefore was an easy target.
It also might have been personal.
Either way, he staked out that house enough to learn Marion's name so he could verify AFTER, so it wasn't completely random.

For some reason, Steward decided that Marion deserved to be squirreled.