Originally Posted by amenas

Indeed 3 holes on a back side are almost evenly spaced and in a line, so it could be some kind of structure, but spikes should be long, very strong and thin. No such structure comes to my mind. I doubt it is possible to stab this way with a screwdriver (it wouldn't come through all these layers), you need something like awl.

It was impossible to notice such damage at the airport. I noticed just completely ripped plastic packing (back pack was packed to the plastic bag in Asuncion at the check-in desk), some scratches and few tiny material irregularities, looked a bit like some thread was puled (these were front/lateral holes). My first thought about these tiny material damages was that it could happen during transportation or anywhere else (e.g. trekking in a forest).

I have noticed all damages just at home, then unpacked everything. At first I noticed just one hole in a jacket and started thinking how and where this could happen on a new jacket. Later checked everything and found every item to be with tiny holes. Rolled back jackets and holes were in line, so it became 100% clear they were made while jackets were rolled (and they were rolled just during this trip while in a back pack). Lastly inspected backpack and found entrance holes. I had no travel insurance.