I suspect that this story is poorly written. I’ll bet a shiny new nickel that the expert something to the effect that a) the acid would dissolve parts of the mouse, leaving clear signs, b) the mouse that was sent to us was completely undissolved, ergo c) the mouse was never in a can of Mountain Dew.
I’d be curious to hear the results from the FReepers who indicated their willingness to try the meat-in-the-Mountain-Dew experiment. IMO, the container should be sealed and meat allowed to soak for several days, to come as close to the alleged circumstances as possible.
I think you’re right about what the expert probably really said. As for the meat experiment, my science teacher when I was in middle school put some chicken bones in a cup of vinegar (or maybe it was coke) and set it aside for a few days. The bones became like rubber, because the vinegar dissolved the calcium but left the protein matrix intact. With more time the protein probably would have dissolved too.