How does this mishna relate to a car crash?

(ה) זה בא בחביתו, וזה בא בקורתו, נשברה כדו של זה בקורתו של זה, פטור, שלזה רשות להלך ולזה רשות להלך.היה בעל קורה ראשון, ובעל חבית אחרון, נשברה חבית בקורה, פטור בעל הקורה.ואם עמד בעל הקורה, חייב.ואם אמר לבעל החבית עמוד, פטור.היה בעל חבית ראשון ובעל קורה אחרון, נשברה חבית בקורה, חייב .ואם עמוד בעל חבית, פטור.ואם אמר לבעל קורה עמד, חייב.וכן זה בא בנרו וזה בפשתנו.

(5) One came with his barrel and one came with his beam. [If] this one's jug were broken on this one's beam, [the beam's owner] is exempt, because this one has permission to walk and this one [also] has permission to walk. If the beam's owner was in front, and the barrel's owner was behind, [then] if the barrel broke on the beam, the beam's owner is exempt. [But] if the beam's owner stopped, he is liable. [But] if he said to the barrel's owner, "Stop," he is exempt. If the barrel's owner was in front, and the beam's owner was behind, [then] if the barrel broke on the beam, then he is liable. [But] if the barrel's owner stopped, he is exempt. [But] if he said to the beam's owner, "Stop," he is liable. So too [the case of] one who comes with his candle and one with his flax.