Postponing a decision
Postponing a decision is a decision in itself.
Every time you need to make a decision, there is always a default.
For example: When you’re interviewing someone for a position, the default is a “No”.
If you postpone your decision, the candidate will understand that you are not going to hire her.
In that example you should tell the candidate whether you hire her or not. But if you don’t, she will understand that you won’t hire her.
If you can’t make up your mind, then your decision will be the default implicit decision.