Probably 15# with no water but he really just does not have that much gear.

His big 4 or hammock 4 are not bad.
Tarp 12oz
Pack 16oz
Compactor bag 2oz
Nano hammock and suspension probably 16oz
Top bag 19oz
UQ 20oz

Thats 5#5oz

Cook kit probably 5-6 oz
Water probably tablets so next to nothing.
Cheap poncho weighs a few oz.
His everyday stuff looks like 8 oz or so.
Silk johns are maybe 10 oz
Vest 6 oz
Socks 4-5oz
Book ?

He just does not have a lot of gear so figure all his other stuff puts him at 10# Base.
Add 5# of food. Sounds doable but the equipment is really skimpy and not a lot of room for error. I dont think I would feel safe with just a vest or maybe I missed something.

I did not see him carrying any water but I am sure he had some somewhere.
Maybe I missed it.

There is a guy over at BPL, a grounder, that did a super light thru maybe a year or two ago. No cook, very SUL, Climashield quilt etc. I think his base pack was 9#. It was pretty impressive.