Is it possible to desolder the bond wires by overheating a chip?
But what about the bond wires? Is it possible that they desoldered/detached?


The bond wires generally aren't soldered to the chip or to the package. They're pressure welded. 

If the bond wires are embedded in the plastic package material (I believe they will be for most QFN package types), and you heated the plastic beyond its glass transition temperature, you could well have caused the plastic to pull the bond wires apart. But you'd likely see burning of the outer surface of the plastic before you did this.