Spring RTS Engine

Silentwings wrote:

That uses gadget callins, unavailable at widget level... And widget:UnitDestroyed is only called with your own units...

All callins used in that gadget are available too widgets. Check the widget handler or https://springrts.com/wiki/Lua:Callins if you are ever confused about such things. Of course, you would have to handle the difficulty that LuaUI only has access to information that is available to the player running your widget; as such you cannot determine in every case whether a wreck was last owned by a friendly or enemy player, but in most cases you have enough information to make a reasonable guess.