I can see that happening. For example he could've been mentally stuck in a "Australian aborigine" language mode, and experienced some sort of "cat got his tongue" situation where he temporarily couldn't even think or summon english to speak with. So until they started interacting and he was able to wake up those neural pathways then it would come back. So he probably somewhat felt like he was re-learning the language at an accelerated pace since he already had the neural wiring for english.