Van Aert is not telling the truth. Any Belgian rider, except Van Aert and Stuyven, had the mission to react on attacks. The first time, nobody reacted. So, Evenepoel did. As agreed. But he shouldn't have been riding so fast with the Frenchman. The second time, Evenepoel did again what was asked. But there again, he rode way too long and hard in the lead. As we saw later in the Sporza-documentary, the coach Van Thourenhout was pleased with the fact that Evenepoel had jumped along.
That is completely contradictory to what Van Aert claims. But the national coach also thought Evenepoel was leading too fast. But that's another discussion.
Conclusion. Evenepoel was too impetuous in carrying out his task. But he mostly did what the coach asked. Van Aert, for his part, now tells lies to cover up his own failure and the concealment of his bad legs.