Two Time Travel Tricks

I have been reading thrillers in which fugitives manage to stay out of sight, confounding the police or anyone else who might be looking for them. But imagine how a time traveller would be able to stay out of sight. You don't want anyone to find you or know where you are for a whole year? Then just travel forward in time for a year.

Imagine this scenario. Everard travels from June 1984 to a single day in June !987, then returns to June 1984. On that day in June 1987, Shalten briefs Everard about the Bactrian letter, which was discovered in 1985. Some time between June 1984 and the relevant day in 1985, Shalten deletes the discovery of the Bactrian letter. Thus, he deletes his briefing of Everard about that letter. But that does not prevent Everard from arriving back in June 1984 knowing about that letter and able to act on the knowledge.

(I am trying to retrieve some sense from Shalten's confused account here.)