Inconsistant inventory space

In the following sequence of actions, I could drop an object, but not take it back, supposedly due to a lack of space in the inventory:

> look

You are in a large chamber with passages to the west and north.

There are diamonds here!

A formidable ogre bars the northern exit.

> take diamonds

You can't carry anything more.  You'll have to drop something first.

> inventory

You are currently holding the following:
Brass lantern
Wicker cage
Little bird in cage
Tasty food
Small bottle
Water in the bottle
Dwarf's axe
Leporine appendage
Large gold nugget

> throw appendage

OK

> kill ogre

The ogre, who despite his bulk is quite agile, easily dodges your
attack.  He seems almost amused by your puny effort.

> take appendage

You can't carry anything more.  You'll have to drop something first.

> look

You are in a large chamber with passages to the west and north.

Your keen eye spots a severed leporine appendage lying on the ground.

There are diamonds here!

A formidable ogre bars the northern exit.

This seems incoherent. Is this a bug?