Spark Plug Ejected

I was coming off the highway and after a *pfsthhss* from my engine (more like /pfθʃɬ/ for my linguistic enjoyers out there) followed the sound of a brick in a clothes dryer, I coasted my V5 into a nearby parking lot where I discover this.

The threads on both ends looked fine. I put the old plug in without a problem but it was idling rough, so I bought new Denso plugs and it ran like a dream.
The rest of plugs look like this

The second from the top has some residual oil on it, which might be a concern at this point.
Figured I'd document this for the sake of future generations.
BUT, could this have been the source of that chirp from my last post? The noise is gone now.

 

Yes, that was probably your chirp. Not wanting to start a spark pug debate but there is a reason why Toyota put dual electrode plugs in this motor.

 

The exact reason I put Denso 3194s, this image is straight from the owner's manual.
EDIT: I bought this truck at 89k, so the previous owner has left some surprises for me.

 

My 02 Tacoma lost a spark plug one time but that was from the spark plug breaking apart. No idea how that happened but it fried the coil boot as well. I also recall the brick in a dryer sound as well hah.