At a point the team start given excuses to abide by what they promised to do or stop communicating with the community then I can sense the project is scam. How do you determine a project is gone bad and won't fulfil it promise? What criteria do you use ? or you wait for years thinking all will be well ?
I rate scam projects from demand made on the market, I think every project that does not make investors interested will exit scam.
and also the plagiarism whitepaper, I think the project that did that was confirmed to be a scam.