Yes. Before you press the Pick Up button in Projection Master, pressing Undo (Ctrl+Z) will undo your painting on the dropped model one stroke at a time. After you have used Pick Up, pressing Undo will undo all of the mesh displacements that were just transferred to the model (in other words, everything between when you dropped the model and picked it up again). This will only undo mesh displacements; any changes that you made to the texture will not be undone.