Straight from the mouth of a Jann Monk:
There are two points:
1. The extra-dimensional space is not at any particular location within the space of the world in which the rope trick is cast. The end of the rope acts as a point of connection to the extra-dimensional space, though, it is not dependent on the space the rope is in actuality occupying in the 'material' world. The spell clearly reads, that the fixture of the rope is: "as if affixed at the upper end." - Rope Trick, PHB
2. The point of teleportation is that it is, teleportation, not movement. The rope doesn't 'move', and therefore constitute a pulling, as much as change place instantaneously. The rope's location is changed in its entirety, the end of the rope leads to a door in extra-dimensional space; it is not that the door in extra-dimensional space is affixed to the location the rope is originally cast at, i.e., the end of the rope is the door, not the location in physical space where the rope trick was originally cast.
Therefore as the rope is not affixed, nor is it 'move' by the teleportation in anything bar location in the 'material' world, there is no 'tearing' between the physical and the extra-dimentional space. The mage holds the rope, teleports and the party climbs back down the rope for some good old trojan horse style pillaging.
The affixture is not something in material space, it is being pulled from the extra-dimensional door, which requires an action on the rope, yet the rope's form does not change through teleportation.
Just because it is an oversight in the rules, on a meta level, does not mean it isn't possible within the game. Sure, it might be broken, though I think it's development is sufficiently scarce to allow its use in context. The DM can always ban it, she is, after all, the lord of space and time.