So apparently the wind there on one day was like this:
The 6-7km from CR is a strong SE vector. It's not possible for it to be a tailwind and a headwind. There may be a point in the road where it is either of these due to the fact that it's not a straight line, but it would seem difficult to have a tailwind for the first 3km and a headwind for the final 3km.
From Saint-Esteve to CR it's pretty irrelevant given the shelter, but again it would seem extraordinary to have a SW Saint-Esteve-CR, a SE for 3km from CR and a NW for 3km to the finish.
Even if it was a straight southerly (180) which would mean cross-tail on both sections it wouldn't be more than 50% of the climb given that the straight tailwind angles for the two sections are say 225 and 135. So for the 15-16km from Saint-Esteve if we assume consistent conditions it's impossible to say that the climb was done under straight tailwind conditions for more than 50% and that is mostly true for the two constituent parts of the climb.

The 6-7km from CR is a strong SE vector. It's not possible for it to be a tailwind and a headwind. There may be a point in the road where it is either of these due to the fact that it's not a straight line, but it would seem difficult to have a tailwind for the first 3km and a headwind for the final 3km.
From Saint-Esteve to CR it's pretty irrelevant given the shelter, but again it would seem extraordinary to have a SW Saint-Esteve-CR, a SE for 3km from CR and a NW for 3km to the finish.
Even if it was a straight southerly (180) which would mean cross-tail on both sections it wouldn't be more than 50% of the climb given that the straight tailwind angles for the two sections are say 225 and 135. So for the 15-16km from Saint-Esteve if we assume consistent conditions it's impossible to say that the climb was done under straight tailwind conditions for more than 50% and that is mostly true for the two constituent parts of the climb.