Macbook Pro touchpad and mouse motion

On my CTO macbook pro lastest (less 6 months I guess) with a magic touch pad embbed, I have an issue where all fingers motions are translated into mousewheel event.

My CTO is able to click and I log mouse SDL_MOUSEBUTTONDOWN/SDL_MOUSEBUTTONUP event.
When he moves, I log SDL_MOUSEWHEEL event most of the time.

I dig a bit in the code and from my understanding, I must log SDL_FINGER. Is it correct ?

Btw, I have set listener on the SDL_FINGERDOWN and SDL_FINGERMOTION. For each SDL_FINGERDOWN or a SDL_FINGERMOTION events, I log a SDL_MOUSEBUTTONDOWN and SDL_MOUSEMOTION events respectively.
How is it possible ?