Saying someone had struck you when he hadn't? (8,3)

'he hadn't?' is the definition.
I don't know anything about this answer so I can't judge whether this works.

'saying someone had struck you' is the wordplay.
I cannot quite see how this works, but
'someone' could be 'pi' (PI is an example) and 'pi' is found within the answer.
'you' could be 'u' (commonly used in online communication) and 'u' is located in the answer.
This may be the basis of the clue (or it may be nonsense).

'when' is the link.

Can you help me to learn more?