> As long as you didn't use any of the original Skype code, you have nothing to fear (if you're based in Europe)

The original Skype code is clearly not available to anyone outside the original Skype team or some team inside Microsoft. What is publicly available is a binary that is produced from this code.

I made a quite clear explanation of the argument a lawyer would use. This open source client is in effect a pirate copy of the closed source client. I expect it will disappear from Github rather soon.