First off, how does Richtofen changing his uniform have anything to do with him being in trouble with someone?
And yes, Dempsey, Nikolai and Takeo all had their short-term memories erased before all this happened when they were test subjects at Der Riese (presumably) under the watchful eye of Dr Edward Richtofen. But, slowly, the three characters seem to be getting their memories back, as they are starting to question what is going on. Paticularly Dempsey, who I think plays a bigger part in all this than we think. It is a strong belief with good evidence that Dempsey was in Verruckt.