I discovered this on the last revision of 7.2 and discovered the caused randomly. However, unique testing to isolate it, I've been able to reproduce it. When the rescue media boots and starts Reflect, after it loads, it propagates a list of recently accessed image files. A swirling red icon appears on the right side, near the top, that says whether Reflect is done propagating this list of files. If I attempt to close Reflect before this red icon disappears and the list of files has finished propagating, the PC will not restart, forcing a power cycle to restart.
This is also present in 7.2.3906. So, I don't know if anyone else can replicate this issue or not, but, you're welcome to try.
Of course, the simplest solution is to not restart Reflect until this finishes filling out. And, most of the time, you won't be done with Reflect before this list fills up. However, when I test my rescue media, I just make sure the version number has been updated and that it boots. Which is sometimes just short enough time so that the list isn't filled up yet.