The building will still have half its max health, but the shitty health leech will go away. I'm suggesting in a casual way but this is totally serious. Or perhaps couple this skill with "enhanced senses"
if scout sabs his own building then an enemy sabs it within 30 seconds, he gets aids and dies over the next minute ggggggggggggggggggggggggggg
I myself am for having the DoT kept in, but not actually starting until the structure has been sabbed for 60 seconds already.
And it's dead. Just put this in to-do list I can't imagine it being too hard. There's already code to sab a target, can't be too hard to make an "unsab" function.