Door closed + feet present + minimal movement + no noise = workmate disturbed mid-pooh, is clenching buttocks and willing you to leave immediately.
Door open + stall vacant + lid closed + can of air-freshener present + thinly disguised odour of beef = toilet recently poohed in, smears present.
Door closed + one foot present + sound of crackling plastic wrapper = workmate has period
Door closed + soles of shoes visible + groaning + retching + sound of can of chickpeas being emptied into bowl = workmate has food poisoning or bulimia.
Door open + stall vacant + receipt from Target present + discarded tag from new underwear on floor = workmate is dirty stop-out.
Door open + lid closed + traces of white powder present + no recent evidence of bowl or paper use = you work in an advertising agency or record company.
Door closed + four feet present + underwear visible + grunting audible = office Christmas party currently underway.
Door closed + two feet present + sound of box being opened + sound of urination followed two to five minutes later by word "Fuck!" = workmate is pregnant.
Door open or closed + two or more females present + tears + word "bastard" audible = Chad from marketing is the father.