Frogspawn will put out sweeper tenticles, and will sting the mushroom. Best keep in mind almost all corals practice chemical warfare. As a rule corals should not touch each other, or be able to reach out to sting their neighbor.
yeah...my frogspawn was about 3 inches away from an acro frag i have, and i noticed a big white patch on it one day. i had to look at night with a flashlight to see the frogspawn's tentacles zapping the crap out of it.
i just assumed the length of the frogspawns tentacles, was it's reach, but they really stretch out at night.