Download accelerator ruin quality of HD clip?

I heard that when you download HD clips with download accelerator program it will reduce qulity of image.Is that true?

WTF? That means no sense. What would the way you download a movie have anything to do with the quality? Unless the program is unable to merge the file parts, it will have no effect on the video itself. A video is a video, it can not change during downloading.

I have found that some high definition videos can get corrupted, causing fraction-of-a-second pauses. This has only occurred when I've used FreshDownload. Quality loss, like loss of detail, is not possible as far as I know.