As said above, the windshiled is lamanated and even if you can shatter them you still need to break out the window. 
The truth is that a serated knife might have gotten through the window faster (the saw part cutting away att the lamanat). 
The fastest way to resolve that issue would be a saws all. I said it, a good battery powered saws all woudl have made little work out of the window. a close second would ba a good hatchet or axe. A final third would be the Grit blades on, I think, Gerber, but any of the saw blades that are on multi tools would cut/shatter there way through that front window. 
Somthing I haven't seen mentioned here is GLOVES. they would have been able to man-handle the window at the very least had they had gloves. Once the window was smashed there were serveral moments lost, becouse they couldn't move the glass. 
If I may be so bold as to sugest the following things to be in our cars, granted most of you probaly have them. 
Gloves 
Fire extinquisher
Axe, saws all (yes I carry one), something to cut lamanted glass
knife (probably already in your pocket) 
if you are a HUGE rescue person you can purcase this tool 
http://www.extrication.com/glasmaster.htm  But it is costly and it will make short work of the front window. 
Just ideas from a silly person. 
Eric