I was wanting ask if anyone knew why Aussiebulls would recommend...

I was wanting ask if anyone knew why Aussiebulls would recommend a "short" as oppose to a "sell" after a "buy" recommendation. I understand this may come about if the "buy" was wrong but I've seen this happen even when the "buy" recommendation was correct. For example, the buy recommendation for Qantas on 29/05 at $1.5620 was good but on 3/06 they recommended a short at $1.5700 when it would've made more sense to sell given you have stock on hand.