The problem is that Sir Robert Holmes (as he later became) was not known as a person of integrity. Quite the contrary: Major Robert Holmes, as he was at the time of the Guinea sea-trials, was somewhat notorious, as a notable villain. Or at least, he is infamous as the hot-tempered, violent and uncontrollable naval commander whose unprovoked attacks on Dutch shipping and seizure of Dutch goods were directly responsible for starting both the second and third Anglo-Dutch wars.
Holmes had served under Prince Rupert and James, Duke of York, and eventually rose to the rank of Admiral. In 1664, on the very voyage on which he was ostensibly testing the Huygens clocks, he sacked the Dutch trading-stations along the coast of Guinea one by one, seizing goods and property and laying waste the Dutch settlements. On his return he was twice imprisoned in the Tower of London (on 9 January and 14 February 1665), for having gone beyond orders or for failing to bring back adequate amounts of booty (it is not quite clear which).35