Is there a neutrino speed anomaly?

The OPERA collaboration reported [1] an anomaly in the ratio of the speed of neutrinos to the speed of light of (v-c)/c =(2.48\pm0.28 (stat.) \pm 0.30 (sys.))\times10-5. I identify sources of systematic uncertainty that were not considered in the report. A basic assumption in [1] is that the proton time structure represents the time structure of the neutrino flux. In this manuscript, I argue that this assumption can be questioned on the basis of the information available. These additional uncertainties can invalidate the claimed neutrino speed anomaly.