Originally Posted by w00dr0w
I am relatively new to homebrewing, but my best (educated) guess would be that your brew will simply have a lower ABV than intended. It will probably have a less hoppy flavor than intended since you didn't put the hops in for the full boil. It might not be exactly what you wanted but should still be okay!
Bittering hops aren't really for flavor...the majority/all of the delicate aroma and flavor compunds are driven off in the boil. Since he only boiled his bittering hops for 30 minutes, not all were lost, so hopefully the bittering hop was dual hatted for flavor as well or else you will get some unwanted hop flavors.