The CTR drop is the almost inevitable result of his action. Before, there were two identical page titles, and your were higher. Thus, you got the click.
Now, there are two non-identical titles, and so there is less reason NOT to click on your competitor- which is logically if not semantically equivalent to "more reason to click" on him.
The specific word "Every" might give him an additional positive impact, but that can be negated by adding a synonym on yours- I like tangor's "All". Alternatively, you can see his everyman word, and raise it with a more distinguished "Best"