Can a medical ins. company go after settlement money after being notified they had 14 days to file a lien?

in the letter the attorney sent to the ins. company , he told them they had 14 days to file for the money, if they did not file it would be deemed a waiver of rights. The settlement happend 7 months ago and everyone involved was notified and sent this letter. the letter was sent out 6 months after everyone was notified of the settlement. Only one company filed within the 14 day period with the courts.