Free vend

So, I walked up to the vending machine at work pondering eating a Twix, when I noticed slot 67 was filled with Galaxy Caramels. Anyone who works at my company knows what this means...
I inserted my 50p, hovered over the Twix numbers but pressed 67 instead, retrieved my Caramel, pressed the coin return button and retrieved my change... 50p!

Now, I didn't need to put in my 50p - it would have vended the Caramel anyway.

Questions:

1. Does the fact the chocolate is free give me the right to take it?
2. Does putting the money in, giving the machine a chance to take the right amount, absolve me of any guilt?
3. Did it make the chocolate taste any worse?

Never mind.. I've eaten it now!