Howe's threat was not carried out.

There was no massacre.
Across the river at Fort Lee the helpless Washington watched this great disaster.

He had need still to look out, for Fort Lee was itself doomed.
On the nineteenth Lord Cornwallis with five thousand men crossed the river five miles above Fort Lee.

General Greene barely escaped with the two thousand men in the fort, leaving behind one hundred and forty cannon, stores, tools, and even the men's blankets.

On the twentieth the British flag was floating over Fort Lee and Washington's whole force was in rapid flight across New Jersey, hardly pausing until it had been ferried over the Delaware River into Pennsylvania.
Treachery, now linked to military disaster, made Washington's position terrible.