Whats wrong with the 3 tab nail?
All shingles were 3 nailed btw, or had only 3 nails per shingle.
Nail is above the sealant strip, and too far above the tab cutout. Though I’ve seen a few manufacturers instructions say below or above strip. That ones too high regardless.
IT was actually just too high to hit the shingle below it. So not only are the shingles you can see not nailed properly but the row below it also does not have sufficent nailing.
AND… if you were able to lift the tab, the bonding was inadequate. Adhesive strip bonds are the most important component in wind resistance. More important than the fastener. Widespread checking of the bond is often overlooked.
Like I sad “too high”. As Kenton mentioned, unless it was cold and you used a tool to break the seal and lift the tab, the seal(s) not bonding are more of a concern.
Poor bond was also an issue. A replacement is probable the best option. The roof was 12 years old.
Was it leaking? Poorly bonded roofs can sometimes go for a long time with no leakage, so if it might go for a while without leaking, you might want to just comment on what you found and what the potential problems are.
I agree with Kenton, no leak, no wind damage, this roof could last a few more years to come.
Report what you see. 
I just listened to two CD’s by Gerry Aubrey of Blue Bell Consulting in PA on roof inspections met him in person in Vegas last month if you guys ever get a chance to listen to him it is well worth the time.
Thats basically what I did. No leaks presently.
A good wind storm may take care of the roof though.
Thats always a fun one for debate. There are no issues but still installed improperly.
"Thats always a fun one for debate. There are no issues but still installed improperly. "
Plenty of that scenario around.
Not everybody knows how to build using a standard or minimum code of the industry. That must be why we have a job to point it out to the ones that don’t know or aware of the correct way.