2016.03.03 around 18:25-18:30 GMT.
The match started normal, with my ping 4X ms and the rest with typical pings for EU players. No one with ping looking like from another region. But after a while strange things started happening, so I pressed Tab and saw this:
http://i.imgur.com/pK8pyJr.jpg
I checked my ping to 8.8.8.8 and a few other sites - it was normal. After ~3 minutes it fixed itself for about 50% of the players, and for the rest after a few additional minutes.
