We cannot ensure that you actually had the items in your inventory. For all we know, you could have had an all-cobble inventory and claim to have lost a stack of diamonds or iron or something along those lines-- maybe even claim to have had a high-level enchanted tool.
The main reason why people commonly lose their inventories for "unknown reasons" is because the players are the only ones occupying the chunk spaces-- when you die and teleport back to the spawn, the chunks are unloaded because there are no players within the area and the drops go with the unloading.
This might not always be the case, but I have come to that conclusion because I have died a few times-- a couple of times when I was out where nobody had been and I lost my items and a couple of times when there were people around and I was able to recover my items.
