Junction has evidently been overshot. Person's awareness of directly behind is improbable. Nature of road makes course adjustment for guaranteed avoidance impossible. Speed still uncertain. Danger of collision imminent.
Diagonal grip reduces possible consequences of collision.
Reached suitable relative position for the possibility of accurately matching course and speed to that of person ahead. Transferring navigational control to this person. This should simplify the complications. Visual tracking of person no longer possible due to complications in their navigation. Latching on physically to person's backpack.