Comment by jpeloquin
Shifting the topic from research misconduct to good laboratory practices, I don't really understand how someone would forget to take pictures of their gels often enough that they would feel it necessary to fake data. (I think you're recounting something you saw someone else do, so this isn't criticizing you.) The only reason to run the experiment to collect data. If there's no data in hand, why would they think the experiment was done? Also, they should be working from a written protocol or a short-form checklist so each item can be ticked off as it is completed. And they should record where they put their data and other research materials in their lab notebook, and copy any work (data or otherwise) to a file server or other redundant storage, before leaving for the day. So much has to go wrong to get to research misconduct and fraud from the starting point of a little forgetfulness.
I mean, I've seen people deliberately choose to discard their data and keep no notes, even when I offered to give them a flash drive with their data on it, so I understand that this sort of thing happens. It's still senseless.