Linda knows the laws and regulations well and there has been public acknowledgement of access to non public information by Mr. Woodford's team but no specific source is mentioned. Something more than that confession may be needed for Linda to reasonably "know" and then disclose this by formal filing. Kind of like the police needing a signed confession.
There is more to this story than meets the eye as many sleuths here have uncovered. The changing legal and regulatory environments as well as the dialogue moves and counter moves around all parties involved here have created the kind of drama worthy of a generational story. NWBO is the most visible and front running target in this story right now but that could very well change. Best wishes.