The difference between your selling of 'source code' vs the 'raw file' issue is easily understood (I've been in IT a while too)
IF said customer took your source code, and modified it and then either started selling it or representing it as your work, and it was not to your standards, I'm pretty sure there may be an issue with either 1. them making a profit off the source code you created or 2. the alterations of said code were not up to standards of your work and you didn't want them attributed to you.
See, photos (and raw files) can be easily modified and passed around, much more easily than souce code - I've seen adds out on craigslist from start up photographers wanting to buy someone elses raw files to represent as their own. 9 times out of 10 someone wouldn't sell their wedding files to another photographer, and then there is that 1-10 percent that would sell them and not even know there was anything wrong with that - thinking since they 'own' the raw files , that they 'own' the rights to do as they please with them - and copyright is a different animal than photo file 'ownership'.
Again, jmho.
Godox/Flashpoint r2 system, plus some canon stuff.