Because in the end, he felt older than he looked and she appeared younger than she acted. They practically counter balanced each other in the long run.

Again, her naïveté made the better of her with her recent comment in vegetables. She obviously never cut an onion in her life, however, she was about to experience that now. Raven waited patiently for her to do so, and not just that, but feel it while she did so. His patience was rewarded with her upcoming reaction.

"That would be th' onion's fumes. Don't feel too bad. It happens ta a lot of people. Somethin' about its chemical's just makes yer eyes go watery."

He didn't really care about the scientific aspect of it. He just wanted to warn her about it.