In your heart of hearts, do you not have a wee moral twinge about this?
Your club/company suspected that their use of side letters might be contentious so, to prevent the tax man getting wind of things, you elected not to tell the football authorities either, deliberately breaking their rules. According to the LNS commission, they couldn't backdate ineligibility, so they let results stand with a wee slap on the wrist fine that was never going to be paid. If the side-letters had come to light at the time, any impacted player would have been ineligible and all results voided.
LNS may have decided there's a statute of limitations for imposing punishments but that doesn't mean the offence didn't take place.