Cutting up dead on road stuff is a long and well represented trait of field herpers the road over. It does not even need to be herps, or on a road. If its dead it's a chance to research, it is technically illegal though as said.
That point about the pygmy blue tongue, I was always under the impression from speaking to people close to the issue that it was not an amateur but someone quite versed in field herping that made that find, simply that they were not looking for the pygmy blue tongue when they cut open the snake. However I have never heard the name of the person mentioned as I say it was just an impression from how they talked about it.
Out of curiosity did the museum ask you to collect road kill for them and ask you to get a permit to do it on permit? Or were they doing the territory thing and using common sense?