Well, he is the author of numerous widely used open source projects. It is a bit redundant (and useless) to give him a "homework assignment when he has such an impressive portfolio that speaks for itself and of which you can assess the quality.

To be fair, though I know the situation in question: Company A wants to acquire Company B, because their product integrates well and also adds value to a particular niche of their customers. Person is one of the lead developers of Company B's product, and together they have also open sourced one of the single biggest components of their product.

i.e. "You want to buy us because of this, and a decent part of this is on GitHub, running every day, but you'd rather not look at -that- code but -this- arbitrary homework assignment".