From the Guardian live feed:
" 16:57
Villa have had a 96th-minute goal disallowed!
Grealish is tripped on the edge of the area, the play goes on and Villa score but Kevin Friend blows his whistle! He says that Grealish dived (he clearly did not), and blows for a Palace free-kick! Villa will go mad! And they have every right to go mad! (Very Barry Davies voice)."