Your Uber driver will never mysteriously "forget to turn on the meter", have a "broken credit card machine", or any of the other scams taxi drivers pulled on me constantly.
If it is raining or the sun is out or the trains are busy or it is any of one a hundred random reasons - you will have surge pricing. Not just 10-15% extra but 100-150% extra. But don't worry keep standing around for a 30-40 minutes and checking the app eventually the price will come down...