Knights & Knaves Alehouse

So my group is doing TOEE, and in one session they managed to take out Flarinth and crew. However, they failed to completely search the mage's lair (specifically the secret room) that session because 1/2 of the party was dead, and the rest near death, so they headed back to town.

The next day they returned and managed to find the secret room without any encounters (though they did blow themselves up reading the trapped map - mage dead and thief-mage @ -3). So the question I have is, what if any xp reward would they get for finding all of his hidden loot (spellbooks, wand, Mirror, Yellowskull, etc)?

Not counting the mirror or spellbooks (500xp/level/spell - UA), the party will have gained over 5000xp ea.

I can't think of a reason to deny full xp. AFAIK, there's no time limit on finding a monster's treasure.

I kind of figured, but wanted to clarify. Thx.