Factual error: Michael X said that he was going to Trinidad to "liberate his people." This is rather misleading and gives the impression that Trinidad was still a British colony. Trinidad and Tobago gained its independence from the United Kingdom on 31 August 1962 so whatever people he had there were already liberated. Also, when the MI5 agent went to Trinidad to check the whereabouts of Gale Benson, he should not have had the power to order the police to burn down any building as Trinidad and Tobago is not subject to the powers of The Crown.
Factual error: The radio amateur uses the Revox tape recorder "B77" to record the radio conversations. This model came on the market in 1977, and the film is set in 1971.