There is a bug in NonBlockingIdentityHashMap.replace that causes unexpected AssertionError.
Minimal failing code:

new NonBlockingIdentityHashMap<Object, Object>().replace(new Object(), new Object());

Both NonBlockingHashMap and IdentityHashMap handle the case of a key that is not in the structure correctly by just ignoring the operation.

The exception is thrown on assert res != null; from putIfMatch. Probably, res should have been TOMBSTONE instead of null here to mark the absence of the key.