You intentionally end your intervals right after passing other cyclists on the road?
I call it ego leapfrogging by wimpy cyclists.

I grant there may be a weird exception for passing and slowing.

edit: If I'm rolling a good speed and an unknown cyclist hops a draft unannounced, ignores my signals - then I may not own the 10' behind me, but I certainly can influence it mightily if they persist
Re-read that this occurred in FL. No wonder - salt water incursion between the ears. Corroded brain syndrome.