How much difference is enough?

In short - a dribbble team with 150 000+ followers presented the work that looks really similar to mine. This is a team on which journey I was following, cheered for their success and growth.

When the creative has such a huge following base the majority seems to almost blindly believe that they are "on the right side" of things and can do no wrong. And in turn - focus on tearing the other side to pieces.

Naturally, I am raising a question - what are the chances that this work was done on the same grid system, has similar ideas and carries similar green shade. I put them side by side for my own comparison and see so many similarities and not enough differences.

I shared this story on Facebook and received loads of responses and interesting points for discussion. Therefore in return, I want to raise a question back to you - how much difference is enough?

How can this be prevented? What to do when this happens? Are dribbble works fair game as long as they aren't trademarked?

Advice and suggestions are welcome.

P.S. Please read through the comment section to form your own opinion. Link in the comments.