There was a little while when AMD had the advantage, wasn't there? Putting out 64-bit and dual-cores while Intel was struggling with the Pentium 4 architecture.
That is what lead to Intel's behaviour; in doing so they limited AMD free cash flow, and in turn limited AMD ability to fund newer die shrinks. And Intel's main advantage over AMD at the moment is the fact that it is one die shrink generation ahead.
The Intel antitrust lawsuit was on Intel's behaviour in the 90s – it just took until 2005 to finally reach US courts (it was filed with the EC in 2000). By the time AMD had competitive CPUs, Intel had already stopped their practices to avoid further scrutiny.
AMD just stopped being competitive too quickly to gain a proper foothold.