image capture deleted unselected photos from iphone 4s

I've always used image capture to download photos from my phone to my computer. I select a month's worth of photos at a time, save them to a folder and "delete selected after import" when done.

this time there was an error during a video clip, the process crashed. I didn't notice and disconnected my phone. then I noticed my camera roll was empty save 3 random photos and a video. I checked, and all my photos from January were backed up on my computer, but 2 weeks of feburary (over 300 photos) were just gone.

I searched all the forums and used several search and backup programs to try and locate them and nothing worked. poof, gone. they weren't even selected. why would this happen?