Shutter half press still activates VR even if its not focusing
That's right. The back button initiates focus and metering only. Only the shutter button engages VR.
Many thanks for above comments, much appreciated. From further research, it appears that both AF-On and Shutter button can activate VR - I just find it disconcerting that having focused with AF-On button a half press of shutter button can cause VR activation - it wasn't so on my D700. Life goes on
I don't think my D610 does what's been described here, bought in 2014. Maybe there is a firmware out there correcting this issue?