What you can do is just try to load the image in a new Image
object. If an image loads, it will update all other places as well (similar to how if you embed the same image 50 times, once it loads once, they all show). So, in your callback (which I assume is an error callback), just try:
var img = new Image();
img.src = this.src; // this should refer to the original failed image
That'll trigger the loading of that same URL in the new image object. If it works, both will be updated and the one we just created is simply never shown anywhere.