It is emerging, rather surprisingly, that Levy didn't quite capture Sartre's concept of freedom. He seems to be leaving it by bringing together Absolute and Freedom when the two need to be taken separately and then be brought together. Freedom needs to be absolute but Freedom by itself is related.
Sartre signals this when he states that freedom is always situated. For that Sartre isn't trying to suggest any different freedom but that freedom which is to be absolute. This freedom, which is absolute, is always situated. In that sense, Freedom is related to variables outside of it. What is it? Freedom is none other than the being of man, or more precisely stated, freedom is the nothingness of man. This related freedom is certainly then limited, here as a whole, as an absolute freedom. So, the absolute freedom is limited by the external variables.
One need not go as far as CDR to find the talk of limitations in Sartre's thought. Facticity is mentioned frequently by Sartre and he means nothing other than what facticity as a limiting variable. Perhaps not explicitly stated but the manner in which it is mentioned it is nothing too far away from being explicitly stated as such. It is clear, from Being and Nothingness itself, that he wanted to answer the issue of capriciousness. He wanted in no way want an arbitrary or capricious description of freedom, and he made significant, successful, attempts to do just that. If one stops merely at the mention of absolute and understands only capriciousness then their critique of freedom may only be valid if it isn't concerned with the freedom that Sartre describes.
It remains, however, unclear that Sartre's existentialism and marxism are essentially different. Perhaps they are, but it isn't clear why that difference is necessarily to be felt in his conception of freedom.