I say look at the teeth! There is a HUGE correlation between grooves on the teeth and venom injection...for example, if they have the grooves, they are venomous. Another good way, if you have a dead citter on your hands, is to look for a little something we call a "venom gland" usually found leading up to the teeth with grooves for the said venom delivery.
FYI: Tyrannosaurus had a bite 10 times stronger than a crocodile, maybe more. Why would it need any kind of venom? Not to mention there is no place for the gland in the skull, as well as no grooves in the teeth (One of the teachers at my university is the leading scientist in the world on Tyrannosaurs).
Upon skimming the article I neglected to mention that the only lizards mentioned specifically were monitors which, as I'm sure everyone here already knows, have bacteria in the saliva from eating rancid meat that cause the wounded animals to go into septic shock in short order. Kind of like venom. Also, I'd like to see more than circumstantial swelling on this; something like functional morphology, venom effects such as bruising, gangrene (from tissue death) or that feeling of wanting to die (or at least feeling like you have the flu) right after a bite.
Sorry to burst your bubble
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