The Judge's ruling went as far as saying that even if they were a foreign company, as long as they based even a single employee in the state of CA, they had to comply with CA’s labor laws for at least that one employee.
If you recall, a few of the 49ers were "based" in LAX at the time of of their dismissal. I could be wrong, but I believe one even had the legal right to reside in the US. A lawsuit was filed in CA against CX or USAB for wrongful termination using some high profile attorneys. The case went nowhere because the judge concluded that the state of CA had no jurisdiction over the matter.