It depends on where you live. Each country has different meat diseases and bacterium that you have to be careful about
Traditionally in many western countries most meats are relatively safe raw though poultry is often not. But the definition of safe is not universal. Fresh chicken may have some salmonella etc, but unless this is allowed to grow to large numbers of spore it will not be dangerous. There are some bacteria that are dangerous in even minute amounts, but these should be vary rare, and even the cleanest cook will probably still transfer them
So to answer question, when cooking meat (or anything for that matter), you have to consider the amount of food adhering to the utensil, and the time it is exposed to a temperature in which bacteria can grow etc
If there was a formulae it would be something like
food type (risk of bacteria) * temperature * time
In general ground meat has been processed but not overly preserved, so time starts becoming a factor. How long has it been in a warm environment? Bacon is heavily preserved and not a great bacteria home, so you have more time before it becomes a risk. I small smear of bacon juice on a fork is not going to create a dangerous level of bacteria in the 20 minutes it takes you to cook the dish. But I wouldn't risk it for Chicken (in my country due to campylobacter still being a problem)
In the home environment I give anything that has touched raw food a quick rinse under the tap (Which just happens to be collected rain water and therefore full of bird poo :-) ) and sometimes a mechanical scrub with the dishes brush before using it again in the cooking process
There are lots of old wives tales on kitchen cleanliness, but the end result is that bacteria needs water, food, and temperature to grow. If you remove most of these they can't multiple to dangerous levels
From my experience in food technology laboratories, the often overlooked problem is surface oil and fat. These trap water, food and bacteria (the perfect storm). Simple mechanical scrubbing will remove vast amounts of these for short term (period of cooking) cleanliness
This of course does not apply to food that must be cooked for non bacterial reasons, and food known to be unclean. Chicken again is typical of this, and I would hot water scrub everything used with raw or partially cooked chicken
Best Answer
The temperature will have been high enough to be safe, so don't worry.
What you'll get is a darker, quite tasty stock. It's not suitable for everything (it's likely to be cloudy as well as dark) but can be very good. When I first got my new slow cooker it tended to do this, because it runs a little hotter than my old one. Running it on low instead of high (starting with boiling liquid) solved that.
You can also use the concentrated stock you've made, just remember to use much less than you would of normal stock.