Why isn't the pool connection closed for every return path?

[KoTTi97]

I just noticed that in the provided example for Vercel Edge functions, pool connections are not closed for every return path:

import { Pool } from '@neondatabase/serverless';

export default async (req: Request, ctx: any) => {
  const pool = new Pool({ connectionString: process.env.DATABASE_URL });
  const postId = parseInt(new URL(req.url).searchParams.get('postId'), 10);

  if (isNaN(postId)) {
    // --> pool connection is not closed here
    return new Response('Bad request', { status: 400 });
  }

  const [post] = await pool.query('SELECT * FROM posts WHERE id = $1', [postId]);

  if (!post) {
    // --> connection is not closed here either
    return new Response('Not found', { status: 404 });
  }

  ctx.waitUntil(pool.end());

  return new Response(JSON.stringify(post), {
    headers: { 'content-type': 'application/json' }
  });
}

export const config = {
  runtime: 'edge',
  regions: ['iad1'],  // specify the region nearest your Neon DB
};

I was wondering if there is a reason for this or if this may be a mistake.