I only wonder whether it's a bane or rather a blessing to remind cold-blooded professionally successful technocrats, they are the same people as we are.
Perhaps they are not as logical as you would think, and the woman in question is not as stupid or illogical as you would think (i.e. it's not just her looks).
How does logic dictates one shouldn't follow his/her heart, anyway? It's a tricky thing.
But it's also why companies have policies around dating coworkers and subordinates. It's very hard to stay in a company if your boss is dating your ex.
The ever popular Wife 2.0 upgrade (since he has sufficient cache). http://www.funny2.com/wifeandgirlfriend.htm
If this person did for me what that drummer did for you, then I wouldn't have said what I said. More importantly, if I perceived that this person was generally perceived to be like the drummer you mentioned above, then I would have said something else. What I perceived was something closer to the lead singer you mentioned, but minus the good looks (though I'm sure this woman is attractive to some group): kinda blah.
If not that, then you can tell by the fact that she jumped into bed with a married man. And having messed around with another exec, it doesn't take much to see what's going on here.