Don’t know – but this is the type of reply you’ll get until the lawyers return from spending Christmas in the Bahamas or where ever…
Imagine that it would be theft or something similar – like it would if you picked something up from those shops which have goods on display on the wrong side of the check-outs. The black bag is not yours, the property from which you removed it was not yours, the insurence company covering the building got no money from you so will track you down with murderous robots rather than pay out for its loss, and so on. Just because it was there, unattended, it was not yours to remove.
Or are you arguing that it was bank robbery?
Flood.