In 1977, Luhmann presented an explanation for particle pitch angle distributions observed in the magnetosphere based on pitch angle dependent drift speeds. This was a numerical model and was not supported by observations at the time. On November 10, 1977, a large injection event was observed at about 1300 UT with data from synchronous satellite SMS 2 located at about 0400 LT. The subsequent evolution of the injection event was studied here using data from several other satellites, namely, GOES 2, 1977--007, 1976--059, ATS 6, and ISEE 1. Comparing the SMS 2 data with observations from the other satellites, it is highly probable that the SMS 2 ''ion response'' was in reality due to energetic electrons. Using a simple model and drift velocity dispersion, we infer an injection time approximately equal to the observed substorm onset time and an injection source location spread over several hours of local time in the nightside magnetosphere. Injection-associated ''butterfly'' distributions (flux minima near 90¿ pitch angle) in the dayside magnetosphere were detected by ISEE 1 and ATS 6. These distributions are qualitatively in agreement with pitch angle dependent drift rate models, such as Luhmann's.