When Jesus granted forgiveness, He was standing in the place of God. Just "sinning" would not be a wrong against Jesus Himself, - unless Jesus was God.
Wakati Yesu alipokuwa anatoa msamaha alisimama kwenye nafasi ya Mungu. "Kufanya dhambi" tu kusingekuwa kumkosea Yesu - bila Yesu kuwa Mungu.