So Battletech copied Robotech in the 80's and got sued?
Not quite. In the early 80s, a company called Twentieth Century Imports got the rights to release model kits based on the anime series Macross, Dougram and Crusher Joe. They later subcontracted rights for these images to FASA for use in BattleTech, and TCI rebranded the kits as BattleTech units (and often shipped them with stat sheets for the game).
In 85, Harmony Gold licensed the anime series Macross, Southern Cross and MOSPEDA, and edited and rewrote them to make Robotech.
In the early 90s, FASA decided to make a BattleTech toyline to tie in with the cartoon. Among the companies who put in tenders were Tyco (who won the contract), and Playmates. Shortly afterwards Playmated brought out their own robot toyline called ExoSquad, and one figure in the line looked amazingly like a Mad Cat. FASA brought the matter to court. Shortly after this Harmony Gold and Playmates entered into some level of agreement, Playamtes began to release the old Matchbox Robotech toys under the ExoSquad banner, and Harmony Gold countersued FASA with regards to the Macross designs present in BattleTech.
What's important to note is that FASA and Harmony Gold independently obtained rights to the Macross designs.