Given statements like “we don’t torture” that have been proven patently false, and fabrications like the Iraq-Niger uranium scheme, Pat Tillman, and Jessica Lynch, questioning US claims about a speed boat provocation are not unreasonable.
Iran on Wednesday accused the United States of “clumsily” fabricating footage claiming to show Iranian speedboats harassing US ships, as tensions rose amid President George W. Bush’s crucial visit to the region.
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Here is a video found on YouTube
Nothing conclusive there, here’s another
Nothing conclusive there either.
Grainy images, grainy video, bad audio, and US military statements that it happened.
Personally I wouldn’t put something like this passed Iran, but that isn’t enough to say that it did happen - nor is it enough for the White House to say it happened, or for the US military to say that it happened, especially in light of Bush Administration rhetoric surrounding Iran, and the track records of fabrication amassed by both.

I read somewhere that the official Pentagon reports regarding the Gulf of Tonkin “incident” have just been declassified too.
How timely.