Ok, there are a few things that you are missing.
1. To create a good remove in mocha Pro, you need to have a good background track. Your bg track is not very good. You should first focus on this by increasing your search area, turing on perspective and validating the track by viewing the grid or surface button.
2. Your remove layer (in your case the object on the sidewalk) needs to be above the bg track. Layer order is essential. The BG goes below the layer you remove.
3. You have no clean frames in shot. Mocha Pro uses clean frames found temporally in time from other frames to remove foreground objects. In a shot like this when the remove layer is on the same exact plane as the bg track (removing a stain off the ground). The stain exists in every frame.
You will need to paint 1 frame in Photoshop or another paint app and feed that to mocha so that it can track it in and match the lighting.
It may benefit you to watch the mocha Fundamentals vide series first:
http://www.imagineersystems.com/video/?tagFilter=mocha%20Fundamentals&&dd=d...
Then move on to remove videos and look for "Clean Plate" tutorials
Best
Ross
Ross Shain
Imagineer Systems
http://www.imagineersystems.com
