During an open colon resection, the surgeon encounters a bleeding vessel. A Crile hemostat is clamped onto the vessel to stop the bleeding. While the surgeon is holding the clamp the CST applies the tip of the activated electrosurgical pencil to the hemostat to coagulate the vessel. Suddenly, the surgeon pulls her hand away, yelling aloud. Upon examination, she discovers a pinpoint third-degree burn on her right index finger.
Explain the principles behind the two possible causes for the burn.