Unfortunately it is your responsibility to double check your personal belongings before you check out. It might be in one of your jacket. or it might be just slip out from the pocket when you just walk to elevater...

The point is, always double check before you leave the room. Most of the time you will get the thing you forgot in the room back. But there is odd times that things tend to disappear forever. When you left room and check out, legally the hotel will not be responsible for the things you loose afterward. Not only Holiday Inn, it is some what common practise around the world. Hotel will always try to identify and look for your personal belongings. But in the end it is your own responsibilities to make sure you did not forget anything.

I would disagree with your conclusion that 'only explanation is that a hotel staff member found the ipod and kept it'. Many things can happen during the moment you start to pack and realise the Ipod is not with you.

I might sound mean. But I do give my sympathy to you. Did you report this to police and obtained one copy of lost claim? Did you have travel insurance cover such event when you were travelling? Life is full with learning opportunities. happy wondering