I was racing the Hamilton AI in career at Spielberg last night and was watching out for this phenomenon. First of all, I had tested the setup (Mercedez) for tyre wear in P and it looked really good - but I also practised making sure I didn't get tyre squeal on turn 2 (I stay in 6th to approach that, which helps I think).
I took an early 1.4s lead (turn 1 at start) and the Hamilton AI was pretty consistent from then on, cutting the gap to within DRS range by the time I was 2 laps from the first tyre change. The Hamilton AI then had to defend against Vettel during my pit lap, so when I pitted my gap had opened to 4s. I had a good lap then on new tyres and maintained the lead when the Hamilton AI pitted. From then on and until the end of the race, I did not see any extraordinary gains by the Hamilton AI. That said, the tyres performed really well and Spielberg was very kind to traction (at least in the Merc).
I also checked the sector times; it was just like Q. Whilst I was faster in sectors 1 and 2, the Hamilton AI was slightly faster in sector 3. This was not like my experience in Canada where one AI suddenly cut the gap by a massive amount. If I spot that at other circuits I will advise; maybe it's a circuit related glitch if it is a glitch.