This episode is of an example of how bad this series has become. The first murder is of a woman pushed into a shallow hole and a small load of dirt dropped in on her. It is not enough to even cover her. So what does she do when she sees the arm of the machinery slowly rotating to get another shovel load of dirt to drop on her? Does she simply sit up, step out and walk away from the hole? Of course not! She instead lies there while fully capable of getting out, watches what she is clearly about to happen and gives a moan of "Oh, no!" ... More dirt comes and she is a most compliant victim.
This is the routine for many of the murders on most of these episodes now. When there are multiple possible responses to a suspicious light, noise or situation like this, a most willing "victim" chooses, out of many more reasonable options, the one thing most likely to get him/her killed. I.e., the script seems more like a parody of a murder mystery rather than a real one.