Is Meursault really the existential hero we thought?

Throughout reading the book it seems on the surface that Meursault is an existential hero, especially because for most of the book he fulfills all 6 tenets of existentialism. While it is written by an author who is one of the forefathers of existentialism the ending of the book seems to question Meursault as a existential hero. We largely see this in one of the the final scenes while he is imprisoned where he is longing for escape or for the chance of survival. He wishes that the guillotine breaks or for the possibility, even if it is 1 in 1000 chance of freedom. He thinks that if there were to be such a thing it would not be as hard on prisoners. These thoughts are very anti-existentialist. For multiple reasons this goes against the foundations of existentialism; specifically the futility of life and the inevitableness of death. Yet he still cannot accept the certainty of his own death. He claims there's something "out of proportion" between the verdict being read and the events that had passed since then. He continues to until the very end to hope that death doesn't come, while he does accept death he does not embrace it.