CRM is something I reserve for returning customers, not for everyone.
You can either send the edit privately, or upload it as a variation of the main file, it doesn’t matter. The former just would save you the bother of uploading, waiting for approval, creating a new preview, etc.
My guess is that the client wanted a song with exclusive rights for branding. They contacted an artist, sent him “Beautiful Day” for reference and asked to do something similar.
You can’t sell exclusive tracks outside the marketplace. However, you can sell your services. So charge him for your time, then send him to buy a license on AudioJungle. You don’t have to upload the edited version.
In any case, even if Tim could prove that it’s a copy of HIS song, what could he claim? The loss of profit, which would be 70% of the cost of the regular license he didn’t get?
Many songs before Tim’s “Beautiful Day” with same feel and chord progression.
Sure, as any other song it wasn’t written from scratch. All we make is based on something we’ve heard before. Doesn’t have to be conscious.
Here’s a good example of how artists copy from one another:
Killing Joke sued Nirvana because they claimed that “Come As You Are” riff was copied from their song “Eighties”. However the lawsuit was withdrawn, because it turned out that the riff didn’t belong to Killing Joke either – they stole it from “Life Goes On” by The Damned. Many others borrowed this riff from the Damned as well. The Damned in their turn admitted that the riff was inspired by The Equals’ song “Baby Come Back” and the Equals didn’t deny that they borrowed it from “Day Tripper” by The Beatles.
You can see it here http://youtu.be/BGCXK09mqog?t=1m9s between 1:09 – 3:25. The show is in Russian but you’ll get the picture.
Chord progression, instrumentation and structure are not copyrightable. You can only copyright lyrics and melody. They are different, so we have no case here.
You should charge him for custom work.
Could be pastiche but not plagiarism. Probably the client said “we want something like Beautiful Day”.