Well - I tried it again tonight - Just barely jacking up on the control arm - At no point did the bolt feel released of pressure.
There is no way that this bolt is going to just 'slide out'.
I could unthread it, but I have stripped way too many bolts this way over 30+ years of working on cars.
Off to a shop, I guess - I hate that (spending $$ for something that I should be able to do, and never sure that they did it right)