I beg to differ.
Museums are like any other place, some good folks, some not so good. Not all museums are the same, I'll agree to that.
I worked for 14 years for a Museum. We were very careful dealing with donations. Proper paper trail, starting from the first phone call from a person enquiring about the process to donate. People I worked with were the best in the field in ensuring proper preservation of the artifacts.
It's a good thing to ask questions first if you're going to give an artifact to a Museum, and some will be ok with conditions you may want specified in the letter they'll give you (I've seen things like "The item shall not be traded or sold to any other institutions or individuals, it should remain in the possession of the Museum and serve for education and research purpose only").
That flag could serve to get discussions like the one taking place in this thread happen in other places too, and the basement of its current owner is one of them