The Weaver was extremely decisive.
From the very beginning, he had only been communicating with Cedric with one of his Weaves. He never revealed his real body.
The death of one of his strongest Weaves was all this powerful Foundation realm cultivator needed to confirm what his foresight showed him.
'This man is danger!'
'I can't stay here for even a second longer than necessary!'
Besides, the technique that was displayed by Brutus, that was not something that mere Foundation realm cultivators are supposed to be capable of using.
This man spelled trouble; he was not staying!
It was a good decision by the Weaver to escape immediately. His pavilion was such a unique enchanted tool that when it relocates, unless the bound owner wills it, it only takes the owner along, leaving everyone else behind.
This was his tested and tried strategy to escape from every danger bigger than he could handle.
