The healing effects by the Treatment Flash spells were superimposed upon the target of healing - or attack, in this case - by Bu Yi's healing spell. As such, Bu Yi's healing stats rose higher and higher, and eventually were 20,000 or more points higher than Codename Sophie's healing spell!
Almost within all the teams tackling this dungeon, the equipment and rewards received were distributed according to each individual member's healing stats or damage output stats. Although in Lin Jie's team, they used the approach of distribution according to one's needs, everyone still craved for better stats innately.
The Priest brothers were exceptions though—they were the typical 'good guys' who would be happy as long as they made the girls in the team happy. This type of personality was often seen in the real world too, so Lin Jie did not feel too guarded about their overly-friendly gestures towards Bu Yi, and did not step in to stop them.