Theory:Doctor Who comic strip discontinuity and plot holes/The Continuity Cap


 * Why did the Doctor's lobster companion in the altered timeline change into Donna, that couldn't have unless she was it, which she obviously wasn't.
 * I think we're supposed to believe that, had Donna not chosen to travel with him that second run-in, Ten would have been met and traveled with the lobster instead. Or something unfortunate occurred in an alternate adventure that resulted in Donna becoming a lobster.