Why do you show Short Sale homes as being sold/unavailable when they are in fact bumpable?

I'm looking for a home in Central Oregon. I've looked at a large number of homes on Zillow and through other sources. I found a home I am interested in and am working with a local realtor.

In providing the CMA for the home I'm now looking at the realtor included a house that Zillow and most other sites are listing as "sold". However, the CMA notes that this is a Short Sale and the offer is bumpable - a new term I learned because there was another Short Sale house I was interested in. An offer was received on this house before I could enter an offer. I asked my realtor if I could still submit an offer. She said I could but unless the Short Sale was listed by the bank as "bumpable" my offer would probably not make it to the bank, even if it were higher than the accepted offer.

She then told me that if the bank had the listing as bumpable, which is how the offer on the house in the CMA is listed, then higher offers would be accepted.

Since Zillow and most other sites show this house as sold, the odds of another, higher offer coming in are remote.

I only make this point because I would have considered making an offer on the house if I had known it was bumpable. As it now stands, the current offer is really only "tentative" until and unless a higher offer comes in on this house.