Causal Stories

Tom has a huge garden and loves flowers. He employed two gardeners who take care of the plants: Alex and Benni. Alex and Benni are very reliable and Tom is satisfied with their work. Nevertheless he wants to optimize the plant growth. He decides to let Alex and Benni fertilize his plants. The magazine recommends the use of the chemicals A X200R or B Y33R. However, Tom also read that it can damage plants when they are exposed to multiple different types of chemicals. Tom therefore decides that he only wants to use one fertilizer. He goes for A X200R. Tom instructs Alex and Benni to buy the chemical A X200R and to use only this fertilizer. Alex volunteers for buying several bottles of this chemical for Benni and himself. After a few weeks, Tom realizes that some of his plants are much prettier and bigger than before but some of his plants are dried up. He wonders whether the drying of his plants might have something to do with the fertilization. He wants to investigate this matter and talks to Alex and Benni. Alex tells him that he followed Tom's instructions and only bought and used the chemical A X200R. However, Benni tells him that he had used the chemical B Y33R instead. He still had some bottles of this chemical in stock at home and wanted to use them up. Tom realizes that the plants dried up in the flower beds on which both A X200R and B Y33R were applied by the gardeners.

Did Alex cause the plant to dry out?