walk out of something—leave a conference, hearing, etc. suddenly (to show one’s opposition, etc.):
- He walked out of the meeting because he was extremely angry, and he didn’t want to say something he would regret.
walk out on something—
1. fail to fulfill an agreement, promises, etc.:
- It remains to be seen if any of the lawmakers who walked out on their responsibilities will pay the price at the polls.
2. = walk out of something:
- Baker told the ministers as much; then, just to make sure they understood how committed she was, she walked out on the meeting.
See also: come out of something / go out of something.