How could he be, regardless of how God impregnated Mary, as she was a sinful human just like the rest of us according to the Bible.
Mary was subjected to the Adamic sin like all other humans, so Jesus had to at least be part sinner himself.
To believe otherwise is just deluding oneself IMHO .
The only way Jesus could have been really without sin is if God created him the same way he created Adam.
What do you think ?