Uhm, I've heard another story about France getting Spanish euros. It seemed that they were not able to produce all the coins and notes they need and they asked the Spanish Fábrica Nacional de Moneda y Timbre to produce some for them. Obviously, we only produce euros with the Spanish designs here.

If this is true, then I understand they may feel embarrased to confess they didn't have the capacity to produce so many coins and notes.

As for Spain giving euro coins when we are short of them, I don't think that's true. At the begining, there were complains about a shortage of coins. But the problem wasn't a lack of coins but problems with deliveries. In fact, many shops complaint banks didn't give them euro coins/notes so that they were forced to take credit cards instead of cash and so got charged commission by the banks.

However, it's been more than a month since the euro was introduced and I don't heard of such problems now. Maybe it is happening in some cases but at least not with the hostels and the shops where I buy.