G'day gents... I'll take a stab at adding to the answer:
There are undoubtedly specific examples of various engine types experiencing this because of specific anomolies, but generally, it's simply the result of the case cooling and shrinking quicker than the turbine rotor.
Clearances are kept to a minimum for efficiency. Some cases are cooled through the use of "Active Clearance Control"... Some (CFM and GE, for instance) use controlled methods of case cooling for both HPT and LPT case sections... - valves controlled hydraulically by the HMU or FCU that permit cooling air flow through the ducting to the case cooling manifolds as desired.
When the turbine rotor is still quite hot, and the case cools relatively quickly, the clearance can shrink to zilch. It's a bit difficult to envision "cooling" of the turbine when you're still pouring fuel into the fire, but obviously at idle for a time it'll be relatively cooler than it had been with some power applied. Usually, as has been said, the potential for this "lock" can be reduced, or is eliminated by observing the prescribed "cool down" period.
I've been told the most common intances of this occurring have been in heliowopwop aircraft with pilots who think it looks cool to come in hard and shut down right away.... They've had some power applied for their landing and the machine is hot.
Cheers,