I’m in two minds about this. It is pretty clever and coins are pretty sturdy, especially ones chosen for a handling collection, so there wasn’t much danger of causing damage. And their legal argument about it never leaving the premises is interesting.
What I don’t like is that they abused the trust of being handed a museum object. As the museum representative says, this just leads to fewer public interaction like that being able to be offered.
Also, they chose an English coin to make a point about repatriation?
ETA: on reflection, the English coin makes sense in the sense of “how do you like it if your stuff is stolen?”