Your two examples merely seem like variations of the squeeze theorem.
Cop pulls drunk example:
If $|a_n - b_n| \leq M$ for all $n \geq N$, and $a_n \to \infty$ then $b_n \to \infty$.
Master pulls dog example:
If $|a_n - b_n| \to 0$ and $a_n \to M$ then $b_n \to M$.