If everything had paused at that moment, allowing a professional research team to set up, they would have definitely been able to accurately analyze the scientific principles and basis behind all these anomalies and changes.
For instance, a new, intense energy source had appeared in the building. The principle behind this source was unclear, but its effects were so peculiar, causing certain components in the atmosphere or perhaps anomalies in the Earth's magnetic field. In any case, the reasons and principles were not important. What mattered was that the dark clouds, lightning, and all other phenomena and changes were rational and not some supernatural events or phenomena.
The only supernatural factor was not the dramatic changes in the environment, but a person in this building, whose abnormality was the cause of the series of intense reactions in the surrounding environment.