The failed assassination attempt on Princess Shunzi was, for Chen Hong, clearly a bitter pill to swallow.
Moreover, the incident was no small matter. The Dongying Imperial Family was enraged, and there was no possibility of them letting things slide. Once the truth was uncovered, Chen Hong had basically no chance of returning to Dongying, including the Chen Family Headquarters, which would surely receive a stern protest from the Dongying Imperial Family...
For him, this was an imminent crisis.
Even if Chen Hong wanted to back out at this point, it was no longer possible.
But he couldn't accept losing his position in the Chen Family because of this, so the crisis from the Dongying Imperial Family had to be resolved.
The best course of action was to turn the tables. He needed to rush back to the Chen Family Headquarters and push all the blame onto Chen Tang's shoulders.