Sorry if this has already been posted, but reviving this thread because I stumbled across a quote that gave me pause and may explain why the family mentioned the bee allergy several weeks into the search. I think it was a dig at Terri based on this quote:
She cant even tell the truth about her divorce or, you know, how she met Kaine, any of that, Young says. Silly little things.
Stories about Kyron getting stung by a bee she cant even tell the truth about.
http://blogs.wweek.com/news/2010/07/10/kyrons-parents-describe-web-of-deception-from-stepmom/
Sounds like maybe at one time TH lied about a bee sting (either lied about how he got stung, or invented a bee sting that never happened) and after all of the info about TH began to come to light and they began to suspect her, they released the info about his bee allergy as a pointed message to TH?