I'll never understand the idea of punishing employees for honest mistakes. Investing the time and money to hire a competent developer, and their ramp up to full

I'll never understand the idea of punishing employees for honest mistakes. Investing the time and money to hire a competent developer, and their ramp up to full productivity is definitely more expensive than that. Not only that, but the new person might make the same or similar mistake in the future. By being understanding you can save money and have the peace of mind that this mistake won't happen again.