Cute story, not that's not how crows behave. They immediately distrust any random human who interacts with one of their dead in any way, and they share their knowledge of who they dislike with their offspring for generations.
They also wouldn't think to bring a flower in particular but would instead bring something of significance to them, such as a shiny object, a nice rock, or some other random small thing.
I've been feeding my local crows roasted peanuts for a couple of years now. They've never given me shit as a present, ungrateful little bastards. One time I thought they left me a little cluster of seeds and berries as a present and I was happy, but then I realized one of them just puked that up so he could eat the peanuts.