As reported on The Verge, Apple won't allow the iPhone to connect to a 4G network until after Apple has tested the phone on the carriers specific network. My guess this complaint is being filed by a carrier that does not offer the iphone, is loosing customers to competitors and like the terms offered by Apple.
Yes, the picture in the newspost is from Mobistar Belgium, the only provider allowed to have 4G on the iPhone. Other carriers already offer 4G as well(and better coverage) but nobody with an iPhone 5 can connect to that network. (Unless they fiddle with an iPad ipcc file OR jailbreak their iPhone and hack commcenter).
Imo it's good that the EU wants to look into it.. Apple has had enough time to 'test' the other carrier's network(which is better than the Mobistar network). They obviously don't allow it because of their contract with that Mobistar carrier.
Not to mention you have to pay full price (800 EUR 32 gb iphone 5): you have an unlocked phone but you are limited concerning LTE. Apple shouldn't impose these restrictions if you pay full price.