Decks, Patios, Porches and Docks - deck posts

A friend built a 10' x 16 ' deck for me . My problem is with the method he used with the deck posts . He dug 18 inch deep holes for each post , filled each hole with concrete , took a hammer drill and drilled a 5/8 inch hole the length of each hole, then drilled a 4" to 6" hole in the bottom of each post . he drove a 2 ' section of 5/8 inch all thread into each hole in the ground, leaving 4 to 6 inches above gound and drilled a 5/8 inch hole into the bottom of each post. He then put a 4 inch washer and nut at concrete level and then another washer and nut was put on the all thread before he drove the post on the above ground portion of the all thread . He used the washer and nut nearest the post as a leveling device but this left the posts sitting up off the concrete by as much as a couple of inches at some posts . There are 5 posts like this on the outer length of the deck , one post in the middle of each short side and one post in the middle of the deck under a joist . The side nearest to house was attached to ledger board . Although the deck is solid feeling as can be , I am concerned that the posts are not in contact with the concrete .The bottom of each post is still slightly below ground level by and inch or so . My question is can I fill the holes the rest of the way up with concrete , which would bring the concrete above the bottom of posts by an eighth to a quater of an inch or am I going to have to replace all the posts ? Thanks in advance for any replies .

I've seen some decks built in pretty unique ways, but none quite as unique as what you are describing!

10' X 16' -- I assume that the deck projects out from the house 10' and runs 16' along the house wall. You mention the 5 posts along the outside edge of the deck, which would make them about 4' apart. What did he use for a girder (or beam) above these 5 posts? And what did he use for joists, from the ledger board to the outside edge of the deck? Then you mention 3 other posts -- " one post in the middle of each short side and one post in the middle of the deck under a joist" -- I'm a little confused about exactly where these are located. 'One in the middle of the deck under a joist' -- OK -- I assume that one is about 5' out from the house, and about 8' in from either edge of the deck. But "under a joist" -- Do you mean that there is no girder parallel to the back of the house, about 5' out from the house? Whether that is OK or not will depend on what he used for joists, and how far apart they are spaced.

Answer my questions, and make sure I'm understanding the layout of this deck correctly, and then we can suggest ways to cure the problems.

Definately a bad way to have them posts.
Here's how I would fix it.
Jack the whole deck up at least a half an inch with a couple of pump jacks on some temporary footings under the main support beam (or make a temporary beam out of double 2 X 12 matl.) Now sawzall them allthreads. Dig out the cement under each post and throw it away. Remove the allthread from the bottom of each post. Get some cardboard form tubing from a local bulding supplier, enough to go a length that is equal to below local frost line (usually 3 feet deep) to the bottom of each post. Dig the ground out to below frost line. Measure and cut the tubing to an exact fit minus what you jacked the deck up evenly to. Burry the tubing in place and fill them with cement. When the cement is still wet, place a short length of 5/8" rebar in the cement and centered over the holes in the posts where the allthread used to be. When the cement has dried and cured, lower the deck onto the new post footings and trim away any cardboard tubing that is above grade.