I would expect from someone like Escalante, a member of Cuba's state security to offer concrete evidence and proofs for his speculation.
1. He names Yaras, Patrick, Cain, Del Valle and Herminio Diaz as the shooters but he does not provide any proof for his claim.
2. You would expect the Cuban security, with all its informants to know the identities of Leopoldo and Angelo, yet in his book 'the Cuba files' says
that Victor Espinoza and Isidoro Borja fit the description of Angelo. I would have expect him to know. If they were good enough to stop Castro's assassination, i am sure they were efficient enough to find out the identities of two lousy Anti-castro Cubans.
3. He claims that the Cuban letters to Oswald were written before the assassination to blame Cuba for the crime, however
two of the letters (Charles & Jorge) are dated before the assassination (10th and 14th November) but the postage stamps were dated 23rd of December if i remember well.
A third, by Lopez is dated 27th November, 1963. The other two are undated. I don't agree with him, i believe the letters were written post-assissination and it was a crude attempt to blame Cuba after the crime. If they had a postage stamp before the 22nd of November, i would agree with him. Anyone can write a letter, date it say 10th of November but send it the 23rd. This does not prove that it was sent the 10th. The important date is the one on the stamp.
4. He insists that Oswqald visited the Cuban embassy, while many researchers believe that Oswald never did and it was an imposter. Again no concrete evidence are presented.