btw, why is the transaction ammount a real number in there? Wouldn't it be clearer to use an integer multiple of whatever the lowest denomination of bitcoins would be?
To be fair, he made that addition before anyone, including probably Satoshi Nakamoto, knew that the Bitcoin "protocol" allowed transaction IDs to change at will for up to ~1 hour after them being sent.
This is exactly how the transaction balance is encoded, as integer multiples of satoshi's (the basic unit of bitcoin, 0.00000001 BTC. All known cryptocurrencies do this to prevent float/double rounding errors.
