the genus might be different but they still fall within the same family which is Ostraciidae, found an article about it. http://www.sciencemag.org/content/146/3641/244.abstract

Also read that the fish must be alive to produce this toxin, so if it dies before producing the toxin, it wont be released into the tank.

That paper you quote says nothing about cowfish, only trunk fish. Same family, different genus and species. Until someone can post a study showing that members of the genus Lactoria or Acanthostracion produce toxins its just heresay.

my experience with cow fish poisonous is when i bought a cow fish and emperor angel at the same time and then put them in a bucket and acclimate them. 30 minutes later, i found my emperor angel is dead so i was scare to put the cow fish in to my main tank. So I put air pump into the bucket and set up a quarantine tank for cow fish. 1 hour later, found it dead also with the white stuff in the water.