Macrophages are a key cell type in the immune system that can promote healing and disease progression. In this paper, we use statistical modelling to revisit the mathematical modelling and in vitro experiments of Ford et al. We focus on experiments that quantify the accumulation of latex beads in macrophages. This combined mathematical, statistical, and experimental approach provides a powerful framework to interpret and quantify fundamental macrophage processes, such as cell division, cell death, and the cannibalistic ingestion and removal of dead cells. We find that the previously reported estimate of a key mathematical model parameter obtained by visual inspection is not contained within the corresponding confidence interval obtained using our objective statistical modelling. We also explore how uncertainty in parameter estimates influences key predictions, such as the distribution of the number of beads per cell. This analysis provides a platform for future studies exploring substance accumulation in macrophage populations.