Most consultancies defend themselves from this sort of behaviour in two directions. Firstly there'll be clauses in the consulting contract stating that the client can't hire anyone who's worked on their project for [n] months after completion (sometimes with the caveat that they can, but there'll be a recruitment fee due to the consultancy). Secondly employees of the consultancy will have non-compete clauses in their employment contracts stating much the same thing.

The interesting bit here is if Star Theory are going out of business then any contracts will presumably become void because one of the signatories has ceased to exist.