I think the major hinge is that BFL needs (someone like) Luke to finish the product. In that respect you can only see Lukes visit as a form of employment, even if they payed him in smiles.
What? No they don't. They promised ASIC mining devices, not mining software.
Again, I went to Sun Microsystems in 1996 to do a tech demo of a Java product my company was working on. At their facility, they gave us early access to the now failed Java workstations to test our product on. You could say that Sun needed some like me to work on Java applications for their Java platform to be viable, but at no time was I ever employed by Sun and indicating as such on my resume would be considered fraud.