Great episode. Freeman is still da best
Considering he didnt know it in the first place, i'd still say no plothole in that. Besides, if he hasnt mentioned sniper doesnt mean he forgot about that too (btw if you notice, his memory has seemingly recovered to full within few episodes after shooting snotmonster). Not to mention the fact, that often people with partial amnesia from trauma (such as blow to the head) remember things when they encounter same or similar situation.
As for finger discussion- fine, show middle toe: it would be ultimate insult (har-har, Monkey island reference) if someone managed to pull this off. I mean have you ever tried to get just your middle toe straight? XD
But if we have 6 fingers, why not the same number of toe ?