I played on server 2 Map 2.07.04 LIMNI.
I was connected as rifleman, bought a truck, a folded tripod (put into inventory) then a static AT launcher backpack (kept on back).
Then my game crashed.
I reconnected as Engineer (cause no rifleman slot was free) and did neither get refund nor had my static at backpack. I had the standard toolbox backpack of an engineer.
I don't know if that is as designed or if it is a bug.