I believe your cousin made an error. As I quoted from the Help Index, on WikiTree, a source is the identification of where YOU found the information. It is perfectly appropriate to add more and better sources to a profile, but in my opinion, it is a mistake to "take down" information added to any profile because it can only negatively effect the person who put it there.
I encourage everyone to never delete someone else's research. If information is in error, please note that in the == Biography == or the == Sources == section with the correct information and your source. If the source is incomplete, please add more or better details, but please don't delete the work other researchers have contributed to the WikiTree.
I think of each profile as a repository for all the information available for an individual, good, bad or indifferent. If there is an error, I correct it with my better source, but I don't delete it. If we remove sketchy sources, you can be sure that in a couple of years some well meaning soul will put it right back on the profile, thinking it is a great find. The only way to correct incorrect sources is to keep them on the profile together with the corrections.