OF course time is not linear. We always have said that Ha-Shem exists outside of “time”. That is why no one has any problem saying how Matan Torah could have impacted Bereisheis (and many other examples in our literature discussing non-linear time).
If you have trouble with visualizing this, I suggest reading the SciFi classic “Flatland” (not about Brooklyn), explaining how a multi-dimensionsal multiverse can exist, even though it is not easily understood by beings (e.g humans) with limited ability to perceive all its dimensions.