There are problems on both sides of this if it goes to court.
1. The disassembly of MorphOS won't match the disassembly of the AmigaOS68k.
2. Changing a program by 25% makes it eligible for a new copywrite... that doesn't refer to an individual subroutine but the work as a whole.
3. If (for example) you have a task of stepping through a linked list to find something the algorythm is likely to be the same or very similar no matter who implements it. It's just the way it's done and is an obvious implementation and arguing they stole the code because their's is similar doesn't mean a lot.
4. Reverse engineering a product to make a compatible one IS legal to some extent.
5. All of the above is subject to interpretation and the argument can go either way depending on how a judge sees it.
