I'm no expert, but I believe the sight words and the phonics are simply two different skills to create proficient readers.

This site says:
"Many of the 220 words in the Dolch list, can not be "sounded out", and hence must be learned by sight. Hence the list is often referred to as "Dolch Sight Word List", and the words on it, as "Dolch Sight Words"."

http://www.dolchsightwords.org/