Knowing that the kinesiology/physiology field uses those terms interchangeably (and there are at least 10 different terms that all describe the same phenomenon) really help you to understand the significance of the test.
For the record, there are MANY ways to determine lactate threshold. There is no "ONLY" way to determine lactate threshold. It is not USUALLY determined by timetrialling. If that were the case, performance labs across the country would be out of business. A true test is performed in a lab setting where conditions are rigorously monitored to ensure that environmental and other conditions do not affect the results.