I like putting felt on too, especially in bad weater locations. If you read the bundle wrapper instructions it says to use extra roof cement under each tab if you are installing in severe weather exposure localities. By my measure this is anyplace in the NorthEast that isn't tucked into the forest trees out of the wind. Near the shore I always do this, especially on the gables and at the bottom drip edge. If this isn't done, then you are relying only on the little dabs of tar that come on the shingles. Also, if the felt isn't cemented down at the gables and bottom drip edge, then the shingles can still come up, WITH the felt. Also, if you are installing in the fall or winter, these gobs of tar won't even melt until spring or summer and you are vulnerable to a winter storm. So...., not only do I use felt, but I use roofing cement (tar in a tube) to secure it to the roof along the entire perimeter and then roof cement the entire perimeter of shingles to it (dabs only, not continuous bead - to let water pass through). In severe exposures (oceanside etc.) I consider it additionally required to roof cement each and every tab with 2 or 3 dots of roofing cement as well. I would insist that your roofer re-do the areas in question with felt.