In dense train networks, the alighting and boarding process involves complex pedestrian flow dynamics. A common rule to facilitate this process is to wait until alighting is complete before boarding. However, many passengers do not adhere to this rule in real-world scenarios. Here we present an experimental study to assess the impact of such non-compliance on pedestrian flow and compare the results with field data collected from infrared sensors. Our findings indicate that pedestrian discomfort increases considerably with increasing non-compliance. However, the average alighting and boarding times are similar regardless of non-compliance levels. We show that this counter-intuitive effect is due to a compensatory mechanism between lower densities at lower degrees of non-compliance and higher densities at higher degrees of noncompliance. This research opens new perspectives in understanding and managing pedestrian flows in dense railway environments.