[4mnt]

> In the case of md5, creating a pair of inputs with the same hash is easier than creating another input with the same hash as something else which you didn't yourself generate.

This is the case with all instances of seeking a collision, due to the birthday paradox [0]

0: https://en.wikipedia.org/wiki/Birthday_attack

[cstejerean]

The birthday paradox helps with the case of finding any two random inputs that have the same hash. The problem with MD5 is that it's feasible to craft two specific inputs that happen to have the same hash.