My VZW Galaxy S3 updated to 4.3 OTA. I tried saferoot. The flash operation seemed to work ok, but when the phone rebooted and the script said it was waiting for the phone to reconnect, it waited forever. The GS3 did reboot, showing a flash screen saying the ROM is "Samsung Custom", but it does not have root. SuperSU says the binary is not there. Rootchecker says not rooted. Phone seems to be fine except for the fact that it is now on a custom ROM. Trying to take it into recovery does not work. I get a very fast flash screen that shows a yellow triangle and says something about the custom ROM. (Not enough time to read it.) It then goes into normal startup. Does anyone have information on how to get past this or undo it? Are there any tools that might help? I experimented with Casual, but it is unable to do anything.