So many (Pree ***) idiots, so little time........

I know what you are talking about and I think what you may have encountered is the worst kind of PreeAss driver.

A PreAss, hypermiler. These are the assclowns that do everything to maximize every drop of fuel/electricity at the expense of every other driver on the road.

You see...... Coasting down and slowly accelerating uses less energy, or so they say. Same with the pulse driving asshats that slowly accelerate to 65 then coast down to 55, slowly accelerate to 65 then coast down to 55 (over and over). Again, supposedly this uses less energy than just going 60....

Anyway, you did the right thing with your communication but next time you also need to get in front of them then force them to use their brakes. They hate that because in hypermiling that's the worst thing ever.