I am not familiar with the platform you refer to but it certainly is unfortunate and one of the main reasons why we do not support third party services. There is a set system in place to help recover stolen funds and proof of ownership of the affected wallet is vitally important. It is not that is was 'allowed' as you stated, moreso the fact that without being able to prove you are the owner of the address in question then an unscrupulous person could attempt to have any wallet frozen for a number of reasons.
I'd prefer to not expand on that one. You're peers are the not the friendliest and anything that seems strange is automatically labeled as FUD...
I'm sure there a lot more people out there who would appreciate help recovering their stolen funds despite learning their lesson with third party services. However that's outside of my scope and just happy to be done. I remember the owner of the platform having issues reporting NRG stolen; all third hand information without truly knowing the details.