Your PCB must be where you do not want a tombstone. A surface-mount passive component, such as a resistor or capacitor, that partially lifts off a pad, stands on end and resembles is determined as a defect per IPC-A-610 specifications. This occurs, when placing and soldering passive, 3,4,5-sided components like resistors, capacitors, and inductors. Tombstoning is generally caused by uneven hearting of the component, uneven solder paste volumes and other causes.
The good news is that tombstone components can be reworked using circuit board rework procedures.