Once you have been cleared after reported, no one else can ever report you for anything, Is that how that works?

No, you can create a thread in the reports forum if you find additional evidence against a player. https://bf4db.com/forum/category/reports

A player is set as "CLEAR" when :

• He has been reported but evidences of cheat were lacking/missing.
• He has been banned but later made an appeal that got approved.

Either cases, if new evidence of cheat are found or provided by someone through a forum report, the player will be banned.