what would cause spark plug gap to close?

[zacmustang03]

ive got an 04 cobra motor in my gt. it recently during a 3 gear pull had a misfire codes we're p0316 p0300 p0302 p0303 p0301. so that seems to tell me cylinders 1,2and3 misfired. well it ran really rough after. I got it home pulled the plugs and 3 were major carbon build up and one had the gap completely closed. these plugs are 2 days old and I gapped them myself so I know it wasnt like this. my question is can a bad coil cause the plugs ground strap to close like this due to detonation?
here are some pictures passenger side

driver side

 

[pharrbear]

had similar problem with my motor which ended up being piston failure/detonation. whats actually closing the j-strap against the electrode is a piece of the top ring which has broken off of the failed piston and is now "floating" around in the cylinder. keep driving and you'll have another spark plug from a different cylinder affected as this ring debris travels from cylinder to cylinder. symptoms especially evident when motor is on boost as top ring pieces are sitting in the lower intake manifold and "freed" with the positive pressure of boost. borescope the suspect cylinder and i bet you'll find piston failure

 

[zacmustang03]

ive had a compression test and all cylinders are good

 

[zacmustang03]

im really hoping its not piston failure yikes

 

[zacmustang03]

okay ive put new plugs in and the car runs like a top fires up right away doesn't smoke or have any ticking sounds . seems fine. I only have a misfire in boost and the car only runs rough once I foul the plugs. The plugs that foul have major carbon build up on them as well. I am also getting a p1152 or p1132 which are rich condition codes. that is I suspect coming up due to the coils not firing and the carbon is tagging the plug as well as creating a rich code from the 02s.

 

[Mystic03]

only way those will close like that is when a piston kiss's them..as far as it being black..are you on a returnless if so your frps could be popped and leaking fuel in the runners smell your oil make sure it doesnt smell like fuel

 

[zacmustang03]

only way those will close like that is when a piston kiss's them..as far as it being black..are you on a returnless if so your frps could be popped and leaking fuel in the runners smell your oil make sure it doesnt smell like fuel

oil is good so is my frps. ive done alot of googling this symptoms and it seems that if my piston was to hit it. the porcelain and electrode etc would of been smashed it literally just looks pushed up as if I gapped it at zero. there is also no sign on the ground strap of contact from any metal