In the US, the final rule of law is "see and avoid". Being behind the other plane you have the benefit of "see" and if you take action that fails to "avoid" a potential conflict, it would be on you.
Is the wording similar in the UK?
This is fun hearing other terms like "cut up". here it would be "cut off".
This is what I pictured when I first saw cut up.
Sliced Seminole