We've had a couple of instances in the past month with InDesign documents linking to different images that happen to have the same name and are in 2 different file locations. It seems that in some instances, InDesign will take it upon itself to relink the wrong images even though those images haven't been touched (either on the file system or in the InDesign file). There has been one occasion where this happened and it wasn't spotted until the document was printed with the wrong images in and today someone noticed while working on the file that an image had changed.

If it helps, these have both been images copied directly out of a .docx or .pptx file where you rename the file .zip, decompress it and then you can directly access the images from there (which happen to be called image1.jpg, image2.jpg, etc.)