No, because as it was mentioned, they had to debug other lines of code not necessarily tied to the battle engine in order to make sure that replacing/adding the new code wouldn't cause a glitch elsewhere. I have some familiarity with C++, HTML, and Java, and based on my own experience, I can tell you that debugging and rewriting code is nowhere near as easy as you seem to believe.
In addition, this isn't some simple little homemade applet, modern games and applications can have millions of lines of code depending on thier complexity, and I would say a High-Def game that runs 24/7 while keeping track of who's logged in and when, while simulating weather conditions on multiple zones is pretty damn complex.