This has happened to me and my group several times while traveling into Zelenogorsk from the North or South Roads and running from Balota from the East as far as Electro. You are just running and looking around, checking loot occassionally, but even without any presses you just get teleported significantly far back and the UI is completely locked up. The only way to start moving again is to restart the client. We are playing on US East servers. Have only noticed this while playing in 3rd person though.