I broke out the error retry logic into a named function that could be
tested independently of the rest of the event processing framework. This
allows the test to know when the retry logic is done.

The problem with the original test was there was no reliable way to know
when it was done trying record an event. A sentinal event was being
used, but there is no ordering guarantee. I could have added
synchronization around attempts tracking to fix the data race, but the
test case was still fundamentally flawed and would error occasionally.