credit score decrease

a month ago, i had my credit pulled by a broker and it was around 805. much to my dismay, another mortgage specialist told me that my score was in the high 780's. he pulled the records and saw that the credit report was run twice by that broker and once today, for a total of three times. he thinks the score is lower because the credit report was ran 3 times. but can it really decrease my score by that much (almost 20 points)? the mortgage specialist at the bank said that i shouldn't worry because it won't change my interest rate... but it's still abit worrisome. thanks!