That first ones just a myth. If youve ever seen a beardie eat a worm youll know it they chew their food pretty good! The only way this I think could have happened, if it even did, is if the beardie was sick, its heat wasnt high enough, and it died right after if swollowed the worm.
Chewing wouldn't make any difference though if it was true.
Because some insect's heads can survive for a little while without the body chewing the body up wouldn't make a difference.