We use strategies like this internally for similar things. I can’t speak to how this would hold up legally speaking, but for informational purposes and being able to show communication and acknowledgement of that communication, it works great.
A couple things, if the button adds a row, the CreatedBy() person would be the person that clicked the button as long as they were logged in to their account.
And for the email, you can use the Gmail pack and also a “CC:” email address to log the same email in a company account as well.
A last line in the email of “If this button was clicked by accident or if you still have questions, please reply to this email” can help a lot too.
Again, not speaking of any legal aspects here, just that it’s really helpful for a log of communication. I’ve seen appreciation of this on both sides too, the person tracking this and the end user that wants a confirmation that they accomplished the task.