Tenants added more to walk-through list 10 days AFTER moving in

[Amy Martin]

This is my first rental and I thought I have found very good tenants...But I'm concerned about this list of "problems" I'm getting from my tenants. 

The lease started from beginning of April but tenants didn't actually move in until this week. On the first day of April, we did an original walk-through together and took notes of the condition of every room/area of the house, then I allowed them extra 10 days to find additional pre-existing problems and add to the move-in checklist. 

However, today I received a supplement list from my tenants, and it states all bedrooms have "Lots of marks, dents, and holes & scratches on all walls". Most of the walls were freshly painted, I have never noticed any marks or holes on the walls, let alone "LOTS OF" them. 

I'm guessing they are saying this to avoid any responsibility for any marks/holes/scratches that may occur during their tenancy? Or, they might have done some scratches/marks/dents on the walls when they moved furniture into the house. I took a video of all rooms on the day we did the original move-in walkthrough, and the video doesn't show any marks or holes on any walls. 

My question is - should I confront the tenants about their statements? Should I go in to the rental and take a look at the walls? I don't want to annoy my tenants by I definitely don't want them to manipulate me from the beginning. I'd love to hear what you guys (all the experienced landlords) would do!