As someone with a background in the hard sciences and having a report that an academic facility has confirmed regrowth, that some arm-chair quarterbacks refuse to actually track down the source and examine it to support their own opinion that contradicts documented cases is not surprising.
As Neal notes even with gland removal there can be errors that leave behind enough venom gland tissue to produce venom in quantities sufficient to cause harm. This also opens the possibility that in a few animals it may even regenerate to a degree. With regeneration being thoroughly documented across many vertebrate species it is foolish to assume it is impossible, however unlikely. Much the same as vasectomy spontaneous reversals can and do occur while surgical reversals still fail with a predictable regularity.
Considering the OP and the nitpicking while not even conceding common ground, it seems that some people just enjoy arguing. I haven't time for that childishness so, I'll urge anyone else that has questions concerning venomoids not being 100% safe to handle to the Liverpool School of Tropical Medicine to find their answer. And, re-iterate that this is really an unethical practice in all but a few scenarios. If you cannot take the time to apprentice with a venomous keeper you really shouldn't consider venomous animals for your collection.