Nice one, and great images,
I would bet that the planters tendon is NOT the problem here and what you have seen is a tear of the free gasdtrocnemius aponeurosis and it has started to scar up and heal, hence the vascularity.
In the short axis I think will identify a normal planters tendon just deep to the area you have imaged. (that is if they have a plantaris)
What I am fairly sure about is that it is not a primary plantaris injury.
Steve