IANAL, but... if it's just a tank truck (water etc) the liability might only fall on the driver. If he needs a hazmat endorsement too, (fuel, oil, etc) then I think there's a good chance the company could take a good hit too. If anyone is riding with him that has the proper endorsement(s), it's possible that they could get cited too. There's also the possibility of the truck getting impounded.
Should you say anything? Morally, yes. Legally, I'm not sure if you're required to. Could you loose your job if someone found out you knew and didn't say anything? If so, who's more important, you or him?
Why doesn't he just go take the test? There is no drive test for either endorsement, although there is the TSA background for the hazmat.
When Injustice Becomes Law, Resistance is Duty
"Our policy should not be informed by our collective outrage about one man's conduct." AG Kamala Harris referring to San Francisco's sanctuary policy and 7 time convicted felon and illegal alien Juan Francisco Lopez-Sanchez.
Originally Posted by 9CA
...Nor may we relegate the bearing of arms to a “second-class right, subject to an entirely different body of rules than the other Bill of Rights guarantees that we have held to be incorporated into the Due Process Clause.”