Happened to me like last week (not in my boss's office though). The person couldn't find out why they could no longer solve the cube. I realized someone else had turned a corner 180° when I recognized an impossible configuration. I solved it easily afterwards.
> The person couldn't find out why they could no longer solve the cube.
If you got to the point where you can routinely solve cubes, i.e. you know your algorithms or you developed a good intuition, then unsolvable cubes should be pretty obvious. Some algorithms are like: if you are in this position, do this, if you are in that position, do that, other positions are illegal. If you are in an illegal position, then you know there is a problem with your cube.
The Rubik's cube is a really hard puzzle unless you know some theory, and the existence of unsolvable cubes is a rather well known fact, meaning that there shouldn't be that many people who are able to solve the cube and don't know about unsolvable cubes.
Or maybe that's just me. I learned on a terrible cube that had a tendency to dismantle itself, so knowing that it had to be put back properly was a requirement for a successful solve.
The fact that the number of positions a cube could be in is greatly curtailed by the limitations of how many positions an assembled cube can transition to was not widely known information for a long time. When I relearned to cube it was news to me. If you haven’t touched a cube in twenty years you might not know.
