Delaney is reported to have testicle grabbed J-Lo, hence the retaliation.
It wasn't a king hit, Delaney could see what was happening, walked up, grabbed him by the jersey and bam, good right hand.
The sad thing is he will get a long suspension. If J-Lo couldn't fight, and just brushed his jaw, Delaney would hit back and it would be all in and both would get 10 mins in the bin. Because J-Lo clean KOed him, he will serve a lengthy suspension.