Blabbing to the press compromises investigations. At the end of an investigation, I agree almost everything needs to be made public to preserve public confidence and the truth. But inviting media/public scrutiny of conclusions makes people avoid certain avenues of investigation. The chances of public outcry suppressing avenues of investigation are probably a lot greater than a member of the public pointing out something that investigators haven't already considered, whether they've disclosed it or not. In the most publicized case of alleged pilot suicide, the U.S. knew the pilot's home country was very upset about that conclusion, and said "deliberate pilot action." Now, the word suicide may be unnecssary in a technical report, but then the other country released a report saying cause undetermined, and the NTSB freaked out and started saying suicide. That's what happens when you bow to the concerns of others during investigations and minimize your findings.
Plus, this guy at Inmarsat does not have all the info. He can say what crucial data Inmarsat has, but he could be accidentally revealing sensitive info without knowing it or be interpreting it incorrectly.
This isn't anything odd - it's regular policy not to comment on the details of ongoing investigations. No good can come of it. If something doesn't add up, say it when the results are released.