A panel of former referees studied the incident were Chelsea full back Branislav Ivanovic put Everton's midfielder James McCarthy in a headlock and appeared to headbutt him, but they decided it was not worthy of a red card.
But both Chelsea and Everton have been charged by the Football Association with failing to control their players.
The melee started after Gareth Barry tackled William and most of the Chelsea team ran to the referee putting pressure onto him to book him and send him off.
Following the free kick, Ivanovic headed the cross down and William scored to give Chelsea a 1-0 win on Wednesday.
The FA also investigated claims made on social media that Ivanovic had bitten McCarthy. The body studied all video footage and contacted Everton and found conclusively he had not done so.
However both clubs face disciplinary action for "failing to ensure their players conducted themselves in an orderly fashion and/or refrained from provocative behaviour".
Barry will now be suspended for the Leicester home game.
The Everton midfielder was set for a two game ban after picking up his ninth booking of the season in the first-half at Chelsea.
But Barry's second yellow, and thus a red, overrules that 10th yellow card of the campaign.
The 33-year-old will be available for Thursday's trip to Young Boys in the Europa League but will miss the Leicester game.
Barry will be back in contention for selection for the return leg with Young Boys as well as the trip to the Emirates Stadium to face Arsenal on March 1.
Gaz must be careful, as if he picks up a caution in North London or before 12th April then he will be hit with a further two game ban.
Your thoughts! Comment Below
Email Bluekipper at firstname.lastname@example.org