Consistently, when a creeper explodes, I can see many destroyed blocks.

When I attempt to walk through these blocks, I get "stuck" (camera jitters, unable to move). Usually, I can escape by placing water down and "floating" out.

When I place a block down (such as water, dirt, or cobble) in an attempt to "fill in" the area in which I got "stuck", that block is replaced by the "original", un-exploded block. For example, if I fill-in with cobble, it might show up as a grass block (and afterwards, behaves as a grass-block)

When this happens, even obsidian can appear to be destroyed by the explosion (until trying to "fill in" with another block, at which point the block becomes obsidian again)