No idea, if the OS design plays into this or if it's just a application design convention, but on desktop Linux how it often works (for example with KDE programs) is that if a program has a file open which was moved (including moved to the trash), then the program will pop open a little persistent notification with a button offering to save the content that you still have in the program to the location where the file used to be, effectively allowing you to recover from such mistakes without hindering you from moving/deleting the file.