Well, your first problem is that you are using "thePlayer" in that script, instead of alivePlayers [ 1 ].
You can try with this:
function DestructionWin ( )
local account = getPlayerAccount ( source )
if isGuestAccount( account ) then
return
end
local wins = tonumber ( getElementData ( source, "Wins" ) ) or 0
setElementData ( source, "Wins", ( wins + 1 ) )
outputChatBox ( "#FFA824The player ".. getPlayerName ( source ) .." won!", root, 255, 255, 255, true )
end
addEvent ( "onPlayerWinDD", true )
addEventHandler ( "onPlayerWinDD", root, DestructionWin )