I wouldn't call it plagiarsm, well not 100%. the designs are pretty simple, anyone can pretty much come up with it and I kind of doubt, well I suppose there is a chance, but really, I'd say it's probable ie. 20% to be sure it's 100% ... there are so many things to account for,

If we were judging by their works @naufal wins by a long shot, (I don't want to get into my opinion on your platform) sadly people aren't measured by their works but by opinions, so I can't say anything more because I don't know, there are many unanswered questions and you shouldn't be quick to judge.

• why didn't fuzzy notice the logo?
• criteria is important (If it's personal choice what to pick)
• we can't be sure what the accused party was doing, so I wouldn't accuse anyone of anything.

well my thinking goes like this, there is a chance he saw the logo and did some minor changes, so that's 50% it's plagerism, but when you think about it the designs are quite rudimentary so I'd say probably, maybe maybe we can bump the odds to 30% :D ....

I don't know anyone so my opinion is pretty much drained on this point, here is another design that is 100% Not plagerised by your quick standards.

https://busy.org/@manuelcruz/bitshares-logo-concept-design