The latter didn't head directly away from here. He still had high hope that these Mutants would take down William. And he wanted to be there when that'd happen.
Yet when he saw how Zin and William started to massacre the Mutants, he knew things were going to end quite bad for him. "Screw it!" he was igniting his spirit power all this into the scroll, and that greatly affected his ability to run away.
If he didn't spare part of his spirit power and attention to activate the scroll he held, he would have increased the distance between him and Ibra, not ending up getting caught up like this.
"Got you!" Just as the last Mutants fell, Ibra was this close to Rick. he moved, hit him with his glaive, ending up sending Rick flying in the air again. "You…"
At this brief exchange, Rick's cloak finally fell off his head, exposing his face. The moment Ibra spotted him, he got overwhelmed with shock, unable to react at the time to follow his hit with another.