A few moments of looking into the scripts:
func int DIA_Lobart_STOLENCLOTHS_Condition()
{
if((Mob_HasItems("CHEST_LOBART",ITAR_Bau_L) == FALSE) && (Lobart_Kleidung_Verkauft == FALSE) && (hero.guild == GIL_NONE))
{
return TRUE;
};
};
So basically, if
Lobart's chest doesn't contain the clothes, you
have NOT bought them from him and
you're guildless, he'll start this "conversation" with you. There are a few minor changes dependant of the facts if you've got them equipped (he'll say he can't believe his eyes) and if you're are working for him right now (he'll call you a lazy scoundrel), but there are basically three options for you:
a) give the clothes to him (if you have them)
b) tell him you don't have them (logically, if you don't have them)
c) tell him to piss off.
If you choose A, you
should be able to buy them back from him normally; B and C lead to a fight.
---
Anyway, if you have the clothes and have a save before him getting angry, you can try to put them back into his chest or approach him and give him the clothes back, buy it and take them again; or you can join a guild, but the quest will probably stay in your quest log for a while; or anyway, a good beating and/or a scroll of Oblivion work most of the time. :P