Been to St Lucia many times but have to admit we never really felt comfortable there. You are probably safe in most of the tourist bits... Rodney Bay, Marigot Bay etc but once you get into Castries and even down near the Pitons, the atmosphere is different. The boat boys are very insistent and many of them drugged-up.

I doubt customs were involved in any conspiracy. Soufriere is not normally used by yachties to clear out. Very often these smaller customs offices are only manned by one person, at certain times of the day. If the staff get delayed, the office stays shut.

I think these people were just in the wrong place at the wrong time. They were new to the Caribbean and maybe weren't cautious enough about where they went. I'm pretty certain Vieux Fort is not recommended in the Doyle guides but I haven't got the book with me so can't confirm that. We certainly never went there despite it being the nearest anchorage to the international airport.