If you really knew what caused what with the bitcoin price, that'd be really special information and you'd be a very special person.
You can make your best guesses as to which forces will dominate. And you can be wrong.
These dynamics change as the scope changes.
Look at the spam attack - Bitcoin was all but unusable, and the price went up.
I don't really think this is true. There might be some bitcoin enthusiasts who hold this view, but I haven't seen any evidence of this belief in the wider finance community.
I thought it was pretty established that (a) that was Willybot (b) there was no exchange you could actually get dollars out (so, not Mt. Gox) of where the price was over $1000.
Honestly, anybody that left USD or BTC funds in Gox wallets for longer than a day deserved to lose them at that point in time. All the reasons were known then just as they are now-- if you don't personally hold and secure the private key, you don't actually own bitcoin. If you can't handle securing it (both from theft and loss) you shouldn't participate in the market as a speculator.
If I remember correctly, the price went over $1k on Btc-e and you could get your money out, but it was always certainly trading lower than a Goxcoin.