I see damage, but I don't see any holes in it.
For composites it is always hard to tell the difference between severe heat/fire damage and real penetration. Once the resin has burned, the fibres are hanging down in rags...
Seems to be more fire on the wing than the engine.
How is the fuel pipe routed on a 777? Where are the pumps located? Could this have been a major fuel system leak instead of an engine fire?
What puzzles me most is not the inboard location of the fire (fuel will run down a penetrated lower wing skin and accumulate there) but the far forward location. For sure fuel does not flow uphill... Is the nose down attitude on ground enough to have fuel running down a lower wing skin running forward inside the wing to fuselage fairing?
The fuel tanks could have exploded?
Most probably not, there was not enough oxygen available for that as the tanks have been well filled. Almost empty tanks may explode, not almost full ones.