We know the broker he uses so if they haven't been involved in any selling then we can assume (without knowing for certain - hence the term "appears") that he hasn't sold any. It helps that he doesn't use a "retail" broker like commsec, NAB, open markets retail or SILA (the old ETRADE).
The broker data is available each evening.
Hope that clarifies.
MartyW
PS the 4 listed above were the 4 main brokers on Friday.
TSN Price at posting:
2.2¢ Sentiment: Hold Disclosure: Held