Bitcoin works very similar to cash in a sense that you have bills that are not divisible. In your case you had a 0.715 354 32 BTC bill, among others. Every input you receive is a single bill and if you want to spend parts of it you will get change [1]. Some wallets allow you to spend "unconfirmed change", Multibit does not by default. Thus your 0.715... BTC are esentially gone until the transaction gets its first confirmation. If you take the TX-Id and watch it with a blockchain explorer you will see that there are two outputs. One for the person receiving your coins and one for your change. Until the change is confirmed multibit treats it as it would any other unconfirmed transactions and acts like it has no control over it.

[1] this is done durring the TX, its not like the other person is actually returning anything to you. Another picture is to imagine lumps of gold. Your 0.715... BTC lump of gold has to be melted down in order to be spend partially.