Slaggy, it's not bloody rocket science. Terrorism is violence which is perpetrated with the express intention of furthering an ideology.
It appears that the man in Chapel Hill probably killed them over some type of neighbourhood dispute over parking and noise.
I'm rather puzzled by those articles you've posted links to, because they seem to be very angry about the religion of people who commit acts like Charlie Hebdo being pointed out, even though the people committing the acts identified themselves as Muslims and their motives as driven by Islam. But when Muslim's are victims they are very definite that it must be loudly pointed out that they are Muslim victims even if it's extremely doubtful if that played a role in the crime. I'm dubious about anybody who would claim that a particular characteristic should only be pointed out if it's in a positive context. That way lies a very dangerous sort of propaganda indeed.
Comparing the Charlie Hebdo murders to Chapel Hill is a false comparison. A more accurate comparison would be the Anders Brevik, Timothy McVeigh or David Copeland cases. If we had denied those were terrorist acts or played down the white supremacist aims, then possibly there might be some sort of sense or logic in claiming that Muslim links to terror were highlighted in a way the aims of white terrorists weren't, or that we denied the label of terrorist for similar acts committed by white people.
We don't do that of course. Nor do we praise people like the BNP or EDL for holding 'moderate' versions oftheir ideology either, which suggests a great deal more sympathy and understanding for those whose views tend towards Muslim extremists than white supremacists. Which always confuses me as they seem to be two sides of the same coin.
Incidentally I saw some extremely distrbing racism towards white people in the wake of Chapel Hill, will try to link.