Short answer. He stakes the whole case on it. When a demurrer is filed without leave, the accused waives the right to present evidence and submits the case for judgment on the basis of the evidence for the prosecution. If the demurrer fails, there is no defense evidence to fall back on — judgment follows.
What the law says
When the demurrer to evidence is filed without leave of court, the accused waives the right to present evidence and submits the case for judgment on the basis of the evidence for the prosecution.
Rule 119, Section 23 — Demurrer to evidence. Read the full provision →
What a demurrer is betting on
A demurrer to evidence is the accused's argument, made after the prosecution rests, that the case should end there: the evidence presented is simply insufficient to convict. The court can dismiss on that ground even on its own initiative after giving the prosecution the opportunity to be heard, or on the accused's demurrer, filed with or without leave of court. Filed with leave, the demurrer is a low-risk probe. Filed without leave, it becomes an all-or-nothing wager — because of the waiver the rule attaches to it.
The price of skipping leave
The rule's allocation of risk is explicit. If the court denies the demurrer to evidence filed with leave of court, the accused may adduce evidence in his defense — the trial resumes and the defense is heard. But without leave, denial is the end of the road: the accused has waived the right to present evidence and the case stands submitted on the basis of the evidence for the prosecution. No witnesses for the defense, no documents, no testimony from the accused. If the prosecution's evidence, unanswered, is enough to convict, conviction is what follows.
How leave is obtained
The rule sets a tight, non-negotiable timetable. The motion for leave shall specifically state its grounds and shall be filed within a non-extendible period of five days after the prosecution rests its case; the prosecution has five days to oppose. If leave is granted, the demurrer itself is due within a non-extendible period of ten days from notice, with a like period to oppose. The word non-extendible appears three times in the provision — these are deadlines no motion can stretch. And whichever way the court rules, the order denying leave or denying the demurrer shall not be reviewable by appeal or by certiorari before judgment.
A decision to make with counsel, coldly
Filing without leave is sometimes a deliberate strategy — where the prosecution's case is so thin that answering it would dignify it — but it should never be a drafting accident or a shortcut taken because the five-day window for seeking leave slipped by. Before the prosecution rests, the defense should already know which route it will take: seek leave and keep the safety net, or waive it with eyes open. The choice belongs to the accused on advice of counsel, weighed against how the prosecution's evidence actually came out — not against how it looked when the case began.