Add to that an angry mob - one that set this woman up - just so this deadly train-wreck of a moment could happen. Of course the whole things was a test for Jesus and His adversaries were willing to let this woman become a casualty of their schemes.
Can you imagine being asked by such a mob to give an opinion on how they should honor the Law of Moses? It wouldn't have taken anything for them to turn on Him - maybe that was their only plan.
How did Jesus manage to always come up with answers like the one He gave on this day: "Let him without sin throw the first stone." Over and over - when put on the spot - Jesus came up with a gem. When put on the spot - as often as not - I do not come up with a gem. I come up with something spectacularly forgettable - or worse - something I wish everyone would forget.
It seems that at least part of His ability to do so though was rooted in His understanding who He was, what He was there to do, and who He was there to speak to. Perhaps at least some of the "authority" that He spoke with that was so different from how everyone else spoke - was He wasn't "trying" achieve His own agenda. He wasn't out to promote Himself. He'd done His soul-searching for forty days in the desert and every day after that. He wasn't attempting to accomplish impressive goals.
He was there to show us the Kingdom - and He was amazing at it.
No wonder the down-trodden and oppressed loved Him.
No wonder His enemies were terrified of Him.
This is still who He is.