Are you sure the leaves are part of the cilantro? If I remember correctly, ours didn’t have any leaves other than the lacy ones with the seeds on top.
I have no doubt. Cilantro leaves can easily be mistaken for the leaves of "flat" parsley.
I use a lot of parsley in a clam sauce I make on a regular basis. I will never forget the time I asked my husband to go out and cut me a bunch of parsley for the sauce. He had no problems doing so and when he came in with it he rinsed them off and was about to start chopping, when I asked him why he brought me cilantro and not parsley.
Bless his heart, he was a good sport about it and went back out and got the parsley.
I was able to tell by the smell of the fresh cut herb he had the wrong one.
The ironic part here, he's the one that turned meon to using cilantro!!!!!