I think the Sheriff's Dept reply is well done. If anything, I'm surprised they didn't simply ignore the inquiry. For the sake of a web blog like this, if you weren't there, you just can't know for certain what happened. Here is the best I can observe from this limited info.
The OP is stating that his crew didn't know where the valves were. This isn't relevant to compliance and causes me to wonder why he is trying to oversell his case.
Assuming FL has similar requirement to anywhere else I've been with these laws, it isn't simply enough to turn the valve. It must be secured, locked, handle removed, etc to comply. I suspect he knew that too, but didn't admit it.
Police officers make mistakes. However, for the very few they make, they are accused of thousands more. As a generality, pulling your weapon is as much a liability as protection and an officer typically won't do it unless absolutely necessary. They are highly trained, scared straight you might say, in the consequences of improperly discharging a weapon. That can only happen while out of the holster. Again, mistakes are made.
So no, I can't know this wasn't one of the few bad mistakes or over reactions. The odds are that the crew did something that the officer legitimately assessed could become a threat. Whether it was or not, is not the standard. He/she has the right to ensure they return home to their family from a job checking for poopy in the river. That would be a pretty lousy mission to die over.
Sorry Minnewaska -
I and my wife also have had almost the exact same experience in Volusia County Florida and will gladly appear to testify that this particular group of deputy sheriffs in Volusia County Florida do indeed use drastic intimidation and do brandish weapons ..... for MSDS inspections !!!!!!
As a very long term paramedic I can also state that my personal observations are that police/LEOs in general are now trending to an almost uniform disrespect of the general citizenry and treat most citizens as the 'enemy'. Ive also noted increasingly that most LEOs are now behaving simply as 'hired-guns' or mercenaries whose true purpose is primarily and seemingly to enhance the municipal 'revenue' ... & not much more.
I am rapidly losing MOST of any respect Ive ever had for LEOs; as, they have they in general have started to become 'the enemy' and the general citizenry are vastly becoming their 'prey species'. ... and Im a 'very conservative' person.
It was not the nobility of France that first went to the guillotine at the start of the French Revolution, it was the gendarmes!