Bale left the M & T Stadium with his left ankle in a protective boot and Villas-Boas was enraged by Adam's challenge.
He walked down the tunnel with the Scotland international, who was not booked by referee Jose Carlos Rivero, at half-time and did not spare his criticism later. Had this been a Barclays Premier League game, Adam would almost certainly have been carded.
"I think it is a very nasty challenge from Charlie," said Villas-Boas.
"Charlie came to me and said something about the challenge. I can accept, but I think he should go to the player to say sorry. If he [Bale] escapes hospital, it is because he is very lucky. I can never doubt Charlie's integrity but it is a very, very nasty challenge. Gareth is not OK. He's so-so. His ankle is extremely painful and twisted."
Bale and Adam have previous: When Adam was playing for Blackpool in 2011 at White Hart Lane, his poor tackle left Bale sidelined for three months with ankle ligament damage.