There is a school of thought within psychology concerning the "emotional tone" of an individual that determines how he or she deals with the world in general. That goes according to the emotional tone scale dreamed up by L. Ron Hubbard – yes, the massive egotist and fantasist behind Dianetics and Scientology. There is some merit to the idea, and it would appear that your coworker is basically living in Anger at all times.

Now, I regard psychology as basically a pseudoscience, and psychologists in general as deeply broken people – but the field is not without merit, nor are its conclusions entirely spurious. The reality is that there ARE people who live in nothing but anger every single day,and those people genuinely are toxic to those around them.

You are correct that even the strongest and sturdiest mountain will eventualy be weathered away by storms. In such situations, it is necessary for a man to remove himself from the source of the conflicts if they constantly recur – especially if this is in a romantic context. There is nothing so damaging to a man's productivity or purpose as a woman who cannot and will not control her own emotions.

There are many vices that bring down men, but rage tends to drive away people faster than greed, arrogance, etc. It's just overwhelming for every type of person out there, where as other vices seem more tolerable, because people are not giving off too much negative energy, or because they can be calmly ignored when it is suitable. Man can ignore the occasional silent hiss of a snake, but even the most disciplined and focused people cannot last through endless storms.