We can't be sure, but based on the french independent nuclear authority, this does not look to be accurate. Just the dramatized version of a German anti-nuclear group:

https://www.lemonde.fr/planete/article/2016/03/04/un-inciden...

It is in French, but it is saying that nothing was out of control and out of ordinary small issues. The temperature was a little bit out of the normal during the operations but that is quite common. And they used Boron because it was the adequate procedure in this case but again not out of ordinary. They decided to not use the control rodes that were not operating 'automaticaly' because of the disruption of the flooded system. But manual control was still available if they wanted to. And at the same time, like in a space shuttle, every electric control circuits are mirrored for safety. So the control room A was affected by the flooding but the control room B and the B circuits were ok, unaffected and operational as designed!