It is a pretty widespread tradition to spin things that seem like bad luck as actually being good luck. For example, it is common for people to consider getting pooped on by a passing bird or rain on a wedding day as good luck. But are they really?
No. No, they are not.
There is no supernatural force that provides good fortune based on bad things happening. That’s just silly. Even if there are supernatural forces, it’s silly to think that they would bestow us with good luck because of some sort of bad incident. So then why do we attribute good luck with bad luck?
There are two main reasons. First of all, it is a way to neutralize any bad feelings or anger or panic about the event. This helps to avoid the victim of the bad luck from stressing out and/or retaliating in anger, as in the case of a bird pooping or a baby vomitting. It also helps to avoid letting the occasion be ruined and salvaging it, as in the case of a rainy wedding or tripping in public.
Spinning bad luck as good luck is just another way to calm people down and keep humans from blowing up.