This study characterizes the complexities of decision-making in an investigation-style practical in two case study groups with seven students in an introductory physics course. The students were trying to test a claim in a hypothetical situation about the effects of drag on the time it takes for a cotton ball to fall. Using two videos as case studies, the study focuses on the complexities of students' experimental decision-making centered around three metacognitive skills: 1) planning prior to investigation, 2) monitoring while doing the experimentation, and 3) evaluating the results. We characterize the complexities of experimental decision-making by creating visuals that show the occurrences of each code in each stage of decision-making. We concluded that the group with more complex approaches to experimental decision-making characterized by back and forth between activating multiple metacognitive skills were able to connect the topic to other physics concepts, have more effective conversations around discrepancies of data in multiple trials, and loop back the results of the experiments to the original claim. However, the other group showed a more linear effort lacking planning prior to investigation and evaluating the results. We argue the complexities of experimental decision-making can be an indicator of the presence or absence of some of the metacognitive skills in lab activities, but further studies need to confirm this finding before making a generalizable comment.