Sounds like a good argument to check the sumps on your takes as part of
your preflight. My instructor told me explicitly not to trust the fuel
truck, as PIC it's my responsibillity to make sure he didn't 'fill me
up with water' (was one way he put it).

He taught me to sump the tanks, then verify the color of the fuel
against a white surface. I know that it can take a few minutes for
contamination or wrong fuel to settle to the sumps, but if I _don't_
check, then I lose an opportunity to abort the flight I might have
otherwise had. Basically, it's not a 100% guarentee I'll catch a
problem, but it's certainly better then if I just go on 'faith' (a poor
trait to have in the cockpit, it seems).

First time I fueled at a nice FBO, I felt kinda funny when I sumped and
checked the tank, like the look the fuel guy was giving me was sorta
funny, but I remembered my responsibillity and finished the check.
It's my butt on the line, not his.

I've read stories of turbo normalized planes getting Jet-A because the
fuel truck saw 'Turbo' and read 'Turboprop'.

Anyone else have thoughts on this?