OK It was Austin. Here is a link
In an attempt to speak to your questions I think it is important to remember, that PPV in a High-Rise situation is somewhat different then other applications. The window should not be intentionally taken out in a High-rise until wind direction is known but if the window fails and a wind driven fire condition results, then PPV can be used to help alleviate some of the effect.
As to your other question about the 5mph wind. I try to emphasize to my students that PPV is an augmentation to horizontal ventilation. I realize this my stand in the face of strong proponents of PPV but I strongly believe that my statement is accurate. Once the window is gone, either by the fire causing it to fail or by a firefighter, the smoke movement should be observed. If it reacts the way you want it to, then the process can be sped up by using the fan, if the conditions aren't what you're looking for, then more attention needs to be placed on what happens if/when the fan is utilized. The blower can easily overcome up to a moderate wind but to do so the fan placement has to be perfect or damn close to it. The path must be closely monitored in order to maximize the slight pressure increase from PP. The size of the exit opening(s) need to be watched as well. Every window interior firefighters open inside the structure causes a reduction in pressure, thus reducing the blowers effect.
This, to me, is where the rub exists. PPV requires personnel to actively maintain, evaluate, monitor, correct conditions throughout the operation. Most crews are accustomed to performing ventilation and then moving on to other tasks once they have achieved the desired result.