There is a minor bug in the deselecting marquee tool (control key + click and drag) when you simultaneously try to zoom in or out using the mouse wheel. If you are attempting to deselect objects by holding CTRL and then click and drag, and before you finish your selection you use the mouse wheel to zoom in or out, your selection area gets corrupted. It is as if the start-point of your initial selection window is magically moved infinitely down and to the left in the viewport. So your new deselection area is a box starting from wherever you stopped and finishing with all objects down and to the left.
I am guessing it has something to do with the zoom style changing when you press the control key. You can avoid the bug by starting your deselection box (ctrl + click and drag) and then releasing the ctrl key then using the mouse wheel to zoom, then re-pressing the ctrl key, then finishing your deselection box. But, that that’s a bit cumbersome to remember.
Here is a video demonstrating the behavior.