If we say that the attack by those plants against Zhou Tian was all for naught simply because the plants' calculations were off, then the subsequent situation can only be attributed to Zhou Tian's rather formidable plot.
Theoretically speaking, when Zhou Tian dropped down like that, he wasn't supposed to fare well, and considering the situation at the time, normally there wouldn't have been any problem. Even if Zhou Tian fell from high altitude, as long as he didn't directly fall to his death, it wouldn't have had a major impact on him. But because his position was incorrect at the time, this meant that when Zhou Tian fell from mid-air, he might directly fall there.