As others have said, the deposit scheme will certainly find in your favour and you'll get your deposit back, because the landlord doesn't have timely photos or inventory indicating the walls were in good condition when you moved in.
For future reference, it is quite possible to have a friendly breezy undemanding approach while still protecting your rights. I recommended something similar to my DC, who was delighted to be offered a flat at a good rate in an area with a terrible shortage of rental properties, despite being a student. DC and their flatmate wanted to make themselves as attractive tenants as possible in hopes of staying on for several years. There were a lot of really minor issues when they moved in, most of which they were perfectly happy to live with, but they did need to document them in order to ensure they didn't get charged when they left.
I pointed out to DC that sending the LL this list would make DC look good (caring about the state of the property, attention to detail) and actually was doing the absentee LL a favour too by alerting them to the fact there are a number of things they might need to sort before renting it to somebody else. I suggested a letter like this:
"Hi LL, just for your records, here's a list of minor issues we've noticed on moving in:
some slats in the blind have been replaced with ones of a different colour
stain on bedroom carpet
(etc)
See attached photos.
None of the above needs fixing for us.
The only thing which does need sorting is the bedroom window which doesn't shut properly. Not a security issue so it isn't urgent, but we'd like it fixed before the weather gets cold."