i've had my share of adf and as long as were talking african dwarf, and not the the african clawed frogs, (those albino dwarf frogs you see al walmart are africican dwarf calwed frogs) the betta should cool down, he just might be curious of a new creature, given he spent most of his life in solitude.
just a note about african dwarf clawed frogs (including the albino ones) they get very big,(the size of your fist) he attempted to swallow, and in the process killed a tiny reguar adf, when i placed 3 male albino cherry barbs (full grown) who were harassing my one female, in the clawed frogs tank, (i must have not fed him enough) because after 2 weeks, one day i saw only 2 barbs left, huh the cherry must of jumped out, so i checked around the tank, and nothing, but i thought him eatting one would be a tight fit in his stomach, within the next hour, another barb was gone, and the frog was looking pretty bloated, i removed the last barb and put him back with the female, who i guess without compitetion anymore, didnt have to harass.
recieving larger chromides as a gift, i put a divider in the frogs tank, and put them in, but the frog kept throwing himself at the divider in futile attempts to kill again, (the chromides lived)
my mom rescued an much smaller albino from walmart (why do they put them in those cups, and let them sit there for weeks until they die??!!!)
at first my largers frog ignored them, then apparently (recently) i found the baby frog dead. (i guess being too big to swallow, strangling was the next best thing for him)
*lesson learned: never put a living create in with african dwarf clawed frogs
but your african dwarf frog should be fine, get him a place to take shelter, as they love to hide