Sure.
So I was texting a guy last night for almost four hours, and usually he ends with, "goodnight, talk to you later." But this time he said, "Goodnight, it was nice talking with you." Do you think he was being sincere?
Sure.
If he wasn't sincere he wouldn't have spent four hours texting.
Just changed his wording, don't worry about it.
I enjoy the everyday talking with my wife.
Sometimes, those talks end with me having some famulous insight into something we covered in the talking.
When that happens, I frequently comment that I really enjoyed the conversation.
For some reason, I suspect there was something very satisfying about the conversation for him and he was acknowledging that fact to you.