I do not agree with this text. It stated that Ethereum fell and pulled BTC. Negative, BTC along with other currencies fell, and ETH was the last to fall.

Bitcoin indeed experienced a much more aggressive drop, hitting around $92,000 on some exchanges during this interval.
Here is the corrected and accurate analysis regarding this specific movement:
1. The "Liquidity Wick" at 21:00
The movement you saw was a high-intensity Flash Crash. In the interval between 20:40 and 21:40, the price not only retraced, it "melted" momentarily.
* The Trigger: A massive sell order (estimated at over 1,500 BTC) was dumped into the spot market around 21:10.