Well quick Internet research seems to have two schools of thought. One that the risk is very low and two that composting is necessary. However risks of parasites or other pathogens are much higher than e coli. One article says 2 weeks of stockpiling is enough to kill pathogens
Surely there are other germs in soil anyway? I would have thought tetanus was more of a threat than ecoli. But maybe that's just because I stick horse manure on my plot no matter what it's condition...