Deadliest animals

This is a cool infographic.  Like most such graphics, it raises lots of questions.  In addition to Nathan's question about the wide error margin, I wonder:

• Why isn't the tiger on this list?  They appear to kill more people per year than lions.
  
• It's a little weird to compare animals that directly kill humans with animals that are vectors for diseases that kill humans.  Should tuberculosis be on the list?  That apparently kills 2 million people a year.
  
• What is the deadliness by rate of exposure?  That is, what proportion of mosquito-human interactions result in human deaths?  I expect the proportion of tiger-human interactions that result in human deaths to be quite a bit higher.