But "subject to physical damage" is not logically equivalent to "not protected from physical damage" for whatever that is worth.
There is nothing in the tap rule that says anything about assuming that the run is subject to physical damage.
Admittedly a subtle point, but one from which heated Code arguments could emerge.
And, of course, there could be physical damage to the MC which would not damage the conductors inside it. :angel:
You can have a 3 foot tap that doesn't comply with everything in the 10 foot tap rule but does comply with everything in the 25 foot tap rule and the raceway or cable used is likely to be the main factor that makes it happen that way. There is more to these rules then conductor size and overcurrent protection levels.