[Suicide Junkie]

I am pretty sure that what you were seeing was the following:

The first hits on the planet don't show explosion animations. The damage is calculated, but it is insufficient to destroy a platform (which could have 1000's of shields)
Once enough damage has been done to actually destroy an object on the surface, you see a huge bLast erupt.

The actual damage mechanics are still working properly, but the animations are not intuitive.