KGirl - I've a slightly different take. I think the 7 pm time is what caused the confusion. Several people were confused, so it's worth considering that it's not about "taking responsibility for other people's choices" but about learning and getting better at organizing these events. I know I've gotten better over time.
One thing that I do better is to have an ironclad plan. My message would now include a mention that there will be no dinner. Also, I would confirm on the side with a few close friends and say "5-6 of us will be having drinks after dinner at X". This will create momentum. Another solution is to pick a place with better reservation policy that accommodates your type of event.
No need to stress about it. Live and learn. We all do.
M39 D6 D3 (at S) S 2014-09 D 2016-09
"You can't start a fire sitting around, crying over a broken heart" - Bruce Springsteen.
