The one to be overtaken accelerates during the overtaking process…

Hi Leutz, there are situations where you could bite into the steering wheel. It doesn’t happen often, but from time to time already. Just like yesterday: I was on a federal road and have overtaken a car. During the overtaking process I notice how the vehicle to be overtaken (before constant speed) accelerates strongly. Evident goal: It does not want to be overtaken. So far, so bad. Fortunately I have plenty of torque available and can – although with it in After that the following behavior of the overtaking: light hooves, tight driving up, threatening signs. Now I’m out of my age for spontaneous, unconsidered reactions, so I just continued driving and at some point I didn’t have it behind me anymore, but: What would be the appropriate reaction?? How did I go on driving, ignoring??? Mark marks and advertisements? What would be the exact facts?? ate traffic hazard??