Slightly confused.
I went to vault 15 and saw piles of equipment on the floor. Mostly low level stuff like healing powders and junk parts.
I went a bit deeper, got murdered big time as I was only checking it out with crap gear, but when I respawned it was lost.
That of course is normal, but as I left the spawn tent, I encountered a Brotherhood of Steel patrol and my gear was still on me.
I had lost all the crap I gathered off the floor, but my CA and CA helmet, along with 1000 .45 rounds and my grease gun were still with me.
I know that's a bit long winded, but that's my point. All the stuff I had on me before I entered the vault was somehow given back to me after I encountered a brotherhood patrol, but the stuff I had found inside the vault was missing.