If my boyfriend isn't suppose to be having contact with a friend but is but through 3rd person can he still get into trouble?

Yes, not only him but the people or persons that are relaying the messages may be prosecuted as well.

Yes, no contact means no contact

If the PO finds out about this, then yes, he could have his probation revoked. It all depends on if they find out or not. Why risk it?

If my boyfriend isnt suppose to be having contact with a friend but is but through 3rd person can he still get into trouble?
Yes. A no contact order clearly states no contact through anything or anyone.