A Lava Grief is only a short temp ban. and Lava Kills people before they can stop it. Water Drowns people But they do not burn from it so they can just place cobble above of it it will go. Also Water Goes away faster than lava if you cut off the source.
I know Brandon has done something wrong. But i Believe you should of just temp banned him.
Also Hes Put Alot of effort into his appeal unlike Many others who either say
"I did not do it" or "im Sorry" and "I've removed it now". Besides Like i stated above. Pouring lava on a victim Will kill them if they dont notice. While water the can just block it off.
as Shown Above Placing lava Will reset in jail time or temp ban. And as i stated about Lava is Worse then water. so in my opinion you should unban him.
of Course this is your choice, and no one can make it for you i just hope you listen to my opinion.