This is not true. What he bought with his Amiga is a single-place license. This means he may use it with one machine only. Strictly speaking he has to remove the ROM from the A2000 and erase the harddrive if he wants to use the ROM and ADF images in WinUAE.
Let's face it, everybody uses his/her self-made or downloaded ROM and ADF files on every PC he/she owns without taking care about licenses and such. Yes.
But it's simply not true to say that it's legal. It's not.
Hmm license arguments again. Is it true to say something is legal if it isn't illegal ?
"single-place" license I haven't heard of that one before. So If said gentleman had two A2000s and moved his rom and HD between them he would be qualified as licensed ?
What if he used a backup HD ? And it goes on and on and on. What about Accellerators that copy the ROM into 32bit memory? Is the ROM "active memory" if it has no power ?
There's no need to speak strictly anymore. As long as the licensed product is not distributed I don't think any person, company, or court in the world would even look sideways at someone using a duplicate copy of their amiga product on another device. Even at the same time. The trees are falling in the forest and nobody is listening.
Get Amiga Forever if you have any concerns and you get a handy untility bundle as well. Worth the money.