I suspect that it may be the partial truth. The best spin isn't spun out of whole cloth; it has elements of truth in it. Those elements of truth provide plausibility, and, if the full truth is ever revealed, the spinners didn't actually lie -- they just missed seeing one of the angles.
The implication of the story we've heard is that Ibrahim didn't know that he was transporting anthrax. What did he think he was transporting? Drugs perhaps? He knew he was smuggling something, after all; I think he would assume it was either drugs or cash. This would also explain why he opened the bag; perhaps he actually tried some of the contents on purpose, thinking they were drugs. One could see from this why he would have succumbed so quickly and so overwhelmingly; he would have had massive exposure.
An experienced drug smuggler is also likely to be the kind of person who would know how to transport something like this successfully. He has contacts, he knows who to pay off, he's familiar with where security is lacking, etc.
I'm also reminded of some stories I vaguely remember from a few years ago about some batches of heroin, I think, that had bacterial contamination of some sort. The cases were in Europe -- I think Sweden and Scotland, but maybe I have the details wrong. Probably unrelated, but I just thought I'd throw it out.
That could result in a swift demise.