7, I mean 8 pages on this, ouch.
Rule 16-2 allows the player time to reach the hole without unreasonable delay. This amount is subjective and varies on circumstances.
An additional 10 seconds to determine if the ball is at rest. (This amount of time is fixed.)
An official making a ruling would have to determine what is "enough time to reach the hole without unreasonable delay" in the circumstances, and then add the static 10 seconds to the time. At the point (whether the player himself has reached the hole or not,) if the ball has not fallen into the hole, it is deemed to be at rest and the rest of R16-2 would be applied.
The issue with Langley is at what point, in his circumstances, did the official think he should have been at the hole, then adding 10 seconds.
I hope this helps everyone.