I mean there is some fault with the family, however their wrongdoings should not make them 37.000 poorer. This case, among so many others, just shows that it is too easy for kids to buy things without (them or their parents) even noticing on an ipad. Also, it could very well be that the kid didn't even think twice that it was real money since "paying" was so easy. He could have easily thought it was ingame money noted in Euros.
After at the latest investing 100 there should be a message from within the game / the ios that they are investing a lot of money on a game. Also, there must be an upper limit; especially an upper time limit of investing money in these kind of things. If you invest in these small timeframes, e.g. minutes, then you could argue that you are in a certain way addicted and this should be stopped by the providers of the content by law.
Thankfully the EU is within reach of making law changes to cope with these shenanigans.
Also, the "goods" they received for their money has no face value. It would cost the company nothing to return them their money. It's not like they had to manufacture a certain car that no one else would buy for that price and thus they lose a lot of money for a return. NO, the goods/service they give cost them next to nothing. [of course you could argue that by investing more money as a gamer you have more fun with the game and this is the service. However, with these sums we are talking about, it's not about the fun anymore and just about the rip-off]
These companies must be stopped by law. You can blame the people for being so stupid to not avoid these traps. However, who really needs to be blamed is the game makers and the software providers (including apple, google, MS as operating system providers. Especially apple since they save your CC information so easily and have no next to none consumer protection).