Originally posted by Fila "Mirror flop" is catchy name so it sticks perhaps too much ?
I agree that it is a catchy name and also believe that many people feel that this is an unresolved issue dating back several years through multiple models.
I don't know what a good alternative name might be, but if I interpret the video correctly, your symptom is a total system hang with the mirror in the up position. The original K-5 mirror flop is described in this thread from 2011:
https://www.pentaxforums.com/forums/115-pentax-k-5/144309-k-5-bug-shutter-going-off-itself.html
It was caused by a bad batch of system boards and was addressed by warranty replacement of the defective board on effected cameras. Your problem, though it has somewhat different symptoms, may have a similar cause (bad electronics somewhere). It is hard to say. It is my feeling that this kind of problem is not a generic weak point across is the entire Pentax line.
In any case, I would hope that Pentax is able to provide a warranty solution that works for you and the other users having this problem.
Steve
* Some may point out the "crazy mirror" problem on the K-3 as being "more of the same". The symptoms are different, though, and the people who originally reported it (most were also K-5 owners) have generally resisted calling it mirror flop.