I see, thank you for that insight. But you haven't denied whether these "erroneous" timestamps are possible. So let me ask you directly:
Is it possible for miners to include erroneous timestamps, regardless of how important they are?
If yes, can these timestamps have a negative effect on the inflation schedule or locktimes?
If I remember correctly, the time stamp of a block comes from the average of all of the miners.
And as gmaxwell said, assuming the average of the miners is correct, the block numbers becomes a near indisputable time stamp for
the transactions that come on chain.. within a small error.
Block chain is one of the few things that can give a near indisputable time stamp.