Well you see there is a difference. I have no problem with anyone using Open Source code, but using it and then claiming all work to be yours, that is not correct. In Android, if an OEM decides to use Android they have to state that the phone they sell utilizes Android.
dminer69, has neither said nor given credit to the fact that XCloudcoin is wholly based on ownCloud. I wonder if the "angel investors" know about this. Finally, as you said, this is something new, but innovative? Hardly.
But you are assuming the terms and conditions of ownCloud requires anyone using the platform to disclose it is based on ownCloud. That is like someone using PHP and disclose their website was developed in PHP. No one does that. As a standalone product it might not be innovative, but being re-purposed for crypto it is innovative.
No, that is not a legal issue but rather an ethical issue, which goes to show how untrustworthy dminer69 is. These "angel investors", could put over $25K into this (hypothetically), under the false assumption that dminer69 developed these features for XCloudcoin, only to find out that these exact features are not exclusive to XCloudcoin and can be replicated/used by anyone who doesn't make use of or own XCloudcoin.
It's like paying $5 for a glass of water at a restaurant, only to find out that they serve them for free.
There are plenty technical issues I raised as well in my previous posts.