Yep, that was my reaction to that scenario, too.
I read explanations on forums as to why CY may not have called it the daddy doll, but, it doesn't add up that she would so readily call the brown pony-tailed doll, the mommy doll and yet not refer to the other (female) doll as daddy - if she saw him doing it.
The "mommy" figure was a teenage female figure from the Hispanic Playset. The grandmother and doctor were from different sets. The child chose the grandmother figure but did not identify it as "daddy" ... "daddy" is as familiar to the child as "mommy", so why didn't she identify both figures if daddy was there?
Another question I've had is about the bite. Did Michelle bite someone and the strangulation turned to a blunt force murder? That is a very unusual remark and if we are to believe that she was quite advanced for her age, then I suspect she understood the meaning of biting ... and wouldn't use that word carelessly.