Well, there are proteolytic enzymes in all meat and these will act to break down protein after death. I dont know how those in deer compare to beef in terms of quantity, but proteolytic activity does occur in venison as well.
Here is an informative article:
http://www.uwex.edu/ces/flp/meatscie...ng-venison.pdf
There is another one from Texas A&M but I cant locate it right off. One thing that article stressed is that it is possible to hang venison for a day (or at least overnight) even in very warm conditions because it takes a while for the natural heat to dissipate out of the meat -- assuming proper handling. Bacterial growth is exponential -- meaning the numbers start out lower and doubles every few hours providing conditions are favorable (temperature and moisture). So, it is time at warm temperatures that cause spoilage. This does not happen over night.
A certain amount of moisture is also critical for bacterial growth. So, washing of the meat is not necessarily bad, as long as the meat is allowed to dry rather quickly. It is a constant level of moisture (at the higher temperatures) that enhances bacterial growth. Some hunters "age" their meat for several days in an ice chest with ice water -- but because the temperature is kept so cold, little bacterial growth occurs even though the moisture is present.
Therefore, there has to be a balance between aging and spoilage -- with considerations of contamination, temperature, moisture, and time factors. Let's all enjoy venison this fall. Good luck with the hunt!