Please take him to a vet. I know it's expensive.
If the bruise you're concerned about is the darker region about 1/3 down your index finger in the first picture then i think there is cause for concern. If this is just a shadow or photo artifact than maybe its less of a issue. Serious internal damage could have been done and he needs to be looked at.
I don't normally jump on people in forums, but this time I will make an exception. I cannot believe that you would buy such a beautiful pied without a proper place to house him...and then stepped on him.
I am stunned and saddened.