Help Scary happenings going on

[BOYNSEA]

This has happened a couple of times. I have the wifi flo Nexus 7 which is unlocked running stock. I got the 5.0 update a while ago and it started getting stuck at the google screen every once in a while. After being stuck at the screen for 10 to 15 minutes, the device would boot up OK. This happened around every 2 weeks or so but it would always boot up eventually. Last week I got the 5.0.2 update and this morning my nexus froze at the google screen. But, it never continued to boot up. I was in a permanent google screen freeze. I couldn't get to recovery. I tried wugfresh and eventually I got to the prone android with the exclamation point. I don't know what I did but all of a sudden it booted up.

Can anyone clue me in as to what is happening. It seems to be lollipop. Any thoughts?

 

[Unforgiven]

Both my 2012 and 2013 (unlocked / rooted / stock) did not like the 5.02 OTA. I had to use wugs to unroot and return to stock, but I was able to do it without wiping and it installed like the OTA

As far as rebooting, I had to do the volume up + volume down + power combination a number of times to restart.