You should not have copper joined directly to galvanized. You will get corrosion. There should be a dielectric fitting between the two. I would replace the shut off with brass. As a side note, it is always a good idea to close the shut off valves when your washing machine is not in use.
What we've got here is... failure to communicate. Some men you just can't reach. So you get what we had here last week, which is the way he wants it... well, he gets it.
If its been this way for a long time don't worry about it. If you do not see corrosion now and its been that way for a long time why worry. I think it may have something to do with it being at the end of a line and no path to ground across the two dissimilar materials that is why you don't have corrosion. Just a guess.