premise: Donald Berry, a professor of biostatistics at the University of Texas MD Anderson Cancer Center who was not involved in the study, told The Associated Press in an email that he believes the report is more accurate than the one released by Harvard investigators in May that estimated up to 4,600 more deaths than usual occurred.
hypothesis: Donald Berry was involved to a limited extent in the research. 
reason: The passage states, "Donald Berry was not involved in the study" 