Given the turn down service consisted only of tossing a chocolate on the bed, I'd say 2 euros would have been too much. I do see your point and that is why I posed the question and specifically on the Hilton forum to see if there had been other similar experiences at this property.

I don't think it should have been viewed as a tip as the coins were mixed in with a number of other items (glasses, papers, pens, laptop) on the desk and not in a prominent place. I don't worry about a few coins but if it were theft, it is a concern. I do routinely leave up to $10 in coins laying around because they are a pain if just going to the lounge and then they are out to remind me to take them the next day. If they disappear, not a big deal financially.