Praise be to Allaah.
He does not have to do anything, because this man who entered
ihraam for Qiraan, then he did tawaaf and saa’i, then he saw the people
cutting their hair so he cut his hair, did not intend to exit ihraam and he
remained in ihraam, so he does not have to do anything, because the most he
did was to cut his hair out of ignorance, so he did one of the things that
are forbidden in ihraam out of ignorance, and if a person does one of the things that are forbidden in ihraam out of forgetfulness or ignorance, or because he is forced to do it, he does not have to do anything. End quote.
Majmoo’ Fataawa Ibn ‘Uthaymeen (22/119).