I was cooking a roast and one hour into cooking I tasted the broth and didn't like the flavor so I rinsed the roast really well and noticed that the crock had cracked - it hadn't been cracked when I started. So my question - is the roast still safe to eat if I finish it in the oven or should I throw out the roast because of the crack?
If you rinsed the roast in the crock, chances are good your crock pot cracked because of the temperature shock from the water you rinsed it in.
If the roast hasn't sat at room temperature for more than an hour or so you should be OK to put it in the oven and let it cook the rest of the way. If you have a meat thermometer, you should make sure the internal temperature of the meat reaches about 160°F before eating it. A lower temperature might still be safe however since 160° is the minimum recommended temperature for ground meat, which has more bacteria inside than solid meat. It doesn't hurt to be careful though.
When you tasted the broth was it warm / hot? If so you were into a normal crock cook so transfer to the oven should be no problem.