"e1229" - TCAS should not be followed until you have an RA. So strictly speaking the manoeuvre by SEY054 would have been a non-standard and surely not according to SOP.
TCAS should not be acted upon if it is just advisory, which happens quite often all over the world.
I think what some have said here earlier, we can not know what the various crew heard as readable / audible radio in their cockpits, so it's very judgemental of some to start talking about lack of SA and bad airmanship, when the transmissions we have access to now, might not have been audible for the 2 flight crews involved.
ATC by failing to catch the EK transmission of FL360, was the only one who we know "heard" the full picture. And was probably one of the main reasons he wanted to avoid making a report.
Now this issue with ATC not catching wrong readbacks from flight crews happens quite often, specially in environments where they love to chatter on the radio in their own local languages, such as France, Italy and Spain.
I have though noticed at least in Europe, that Radar control often have full view of your new assigned Flight Levels / Altitudes, after they have given you a clearance, and you have selected this on your FCU.
Can we assume that ATC in this instance did not have such equipment, that they could see what level the aircraft was climbing too?
I have in past heard corrections from Radar Control over the radio for both cleared levels and QNH settings selected.