DS's teacher told me she pulls him separately at times to work with him on advanced level concepts that the other kids don't get, but I have no idea where she finds the time for this. DS still does participate in the reading group. I think that acceleration to another grade for reading is probably the only solution, if there are no other kids at a similar level.

DD is in third grade and they didn't do reading groups at all for most of the year. The teacher taught the whole class the same 3rd grade reading curriculum. DD's solution was to go into a coma and space out. Not sure if that is better or worse than calling out answers.