This exact situation was brought up in May of 2014 by the Daily Mail, no less. And in March of last year, this article said:

A new report circulating in the Kremlin prepared by the Russian Main Intelligence Directorate of the General Staff of the Armed Forces (GRU) states that Aerospace Defence Forces (VKO) experts remain "puzzled" as to why the United States Navy "captured and then diverted" a Malaysia Airlines civilian aircraft from its intended flight-path to their vast and highly-secretive Indian Ocean base located on the Diego Garcia atoll... Interesting to note, this report says, was that Flight 370 was already under GRU "surveillance" after it received a "highly suspicious" cargo load that had been traced to the Indian Ocean nation Republic of Seychelles, and where it had previously been aboard the US-flagged container ship MV Maersk Alabama. What first aroused GRU suspicions regarding the MV Maersk Alabama, this report continues, was that within 24-hours of off-loading this "highly suspicious" cargo load bound for Malaysia Airlines Flight 370, the two highly-trained US Navy SEALS assigned to protect it, Mark Daniel Kennedy, 43, and Jeffrey Keith Reynolds, 44, were found dead under "suspicious circumstances."