That bull doesn't look that nervous to me. In fact, it looks like you took those pics through a spotting scope, from a good distance, not at all hassling him. No harm done unless he can feel your optics burning a whole in him.
I do think it's important to let the animals clear before you walk in, but it doesn't look like your pressuring them at all. Good for you for keeping your distance, and good luck finding them later.