i have seen an image tempororaly burnt on a goggle after it was used then turned off - then lights on in building with goggle pointing up - a shadow was left for a short time - there must be residual sensitivity for some time after switch off - (gen3 ) been carefull ever since
Yes, there is. Turn a Gen3 off and look at a streetlight. You'll still see it.
The MCP will shut down very quickly, however the -800v to the screen and the 1000v or so to the screen is still present and the tube will still act like a Gen1 type tube, just not many electrons make it all the way through to the screen.
But from a photocathode perspective, the tube is still on.
Not every Gen3 I've seen seems to exhibit this, but I've seen it before in Gen2 and Gen3.