OK, so the video clearly shows a vacuum bag and autoclave procedure. Are the ribs bonded to the skins? Are the composite ribs cocured or secondary bonded? Are the metallic ribs bonded?
The other cracks are not on the feet per-se, but on the shape below the feet in between the rib structure and the feet. These are more serious and IMHO, would be grain boundary cracks that could extend quickly depending on grain boundary length.
Grain boundary cracks are usually stress corrosion cracks. The clarifying evidence comes from the direction of cracking. Any designer worth his salt will always align the major loads with the rolling (L) direction, and fatigue cracks will grow perpendicular to the major loads, so they will NOT grow along grain boundaries, they will grow perpendicular to the grain boundaries. In contrast, stress corrosion cracks grow along grain boundaries so they grow parallel to the rolling direction and will be parallel to the span direction.
Stress corrosion cracking require three things: (1) an extruded, forged or rolled alloy which is susceptible to grain boundary corrosion, (2) a corrosive environment (and this may be as mild as the presence of water and some ions) and more importantly the presence of a residual stress such as would result from inadequate shimming or poor fit-up combined with the use of fasteners.
I have seen some STUPID repairs for SCC. The standard issue engineer looks at the SRM and finds "a repair for cracks in this area" and implements that repair without taking due cognisance of the crack direction. Most SRM repairs ASSUME cracks are fatigue cracks. In one case the repair required numerous fasteners to be installed ahead of the crack to be repaired, and the repair did absolutely nothing to provide restraint of crack opening.
I have been involved in a number of repair scenarios for SCC using bonded composite patches and these have been very effective. I just hope that the Airbus solution does not involve punching hundreds of fasteners through the structure to relieve local stresses due to flight loads, because if it is SCC, such repairs will be totally ineffective.
Regards
Blakmax