cant be that big of an oil leak, the sponge still looks pretty clean.

have you tried removing the sponge and checking for evidence of the said oil leak before you start point a blame at a trader.
just that it could have been over sighted, or maybe even left like that from when the trader took ownership of the car

if all said and done and the trader is to blame and its someone from on here then yes its a bit moody and maybe a name and shame may be req'd. but look into it a bit more first mate.

just my opinion