Truthfully, in Crowley's lengthy existence he had only truly Fallen once. When he became a demon, he described it as a vague saunter downwards. After all, all he did was ask questions, start wanting to know a little bit about the ineffable plan She had designed for them all. So he became a demon by asking a few questions and listening to the wrong people and it was a rather gentle process up until the divinity was ripped from the core of his being before being replaced with the darkness leftover by any strong light. So no, he hadn't Fallen, not truly when he had become a demon. Rather he had Fallen due to a conversation with an angel. An angel who went against everything they had to be, really if you looked at them over all. He'd gone against Her plan by giving away his sword because he cared too much. An angel that was not immediately repulsed by the being that had given humanity Choice (and if they ever took a moment to reflect on it in the future, would realize he had also given Aziraphale Choice inadvertently). Had instead listened and disagreed mainly for the sake of having to and had shielded him from the rain in the first act of compassion he had truly felt since he had been one of them too.
Crowley had only Fallen once, he had sauntered downwards into devilry and had almost immediately afterwards Fallen for Aziraphale, Principality of the Eastern Gate.
It had taken some time to realize for him that he carried a new light in his chest. The light of his love, an emotion that for all accounts and purposes he should not be able to feel anymore. A light he could some days swore shun brighter than divinity ever had in his body.
He wondered if Aziraphale felt it too some times.