The protection is real, considerably narrower than most owners assume, and easier to lose than anybody expects. The rest of the decision is bookkeeping and habits.
A probationary period nobody manages is just three months of hoping. It is meant to be a structure with dates attached, and it runs in both directions.
Forty applications and nobody hireable means the advertisement did its job badly. The purpose of the writing is to help the wrong people decide against you.
The month closed with more revenue than costs and the checking account still went down. Both facts are usually true at once, and the reason is almost never an error.
An invoice mailed in early October can sit until Thanksgiving without anybody deciding it should. The sequence that gets it paid is mostly settled before the job starts.