That is not entirely impossible (obviously). I've been in a component factory and I've seen the machines for taping the parts. Basically, parts came in the bags from the manufacturing process and then the operator "fills" vibration bowl feeder with the parts. Machine tapes the parts from the bowl. If operator pours a bag with the wrong parts, they will mix in the bowl and there you are... I suppose the manufacturer did not use part-by-part check (otherwise it will be detected and rejected) or the measuring instrument was faulty and bypassed. In any case, it's an unreliable source. The company I was at made caps and varistors only and EACH was categorized before taping and parts out of tolerance were rejected. Moreover, each part was optically inspected for bad metalization and rejected if bad. On the other side, the flaw in the process allowed operator to put the wrong label on the reel, resulting in the similar problem (althought all parts were the same in that case). It happened few times...

Modern pick and place do not measure passive parts anymore. Older machines used mechanical centering, during which passive parts were (sometimes) measured (R,C,L and diode polarity). At today's speeds (>20.000 CPH) and part sizes (0201 and smaller) it is not possible anymore.