I remember there being legal threads from LucasArts every few years, presumably when new staff at legal got aware of ScummVM. The ScummVM team got used to it but iMUSE was the only part that could actually get them into trouble because it was still patented back in the early days.
Nice to see that Nick Porcino is acknowledging the unofficial implementations in the references, including ScummVM and its now-defunct sister project ResidualVM.