I wanted to tick "insurance will cover it" coz i know how much you like that one ekka! I rate it highly likely. The union is not the worrst it could be but species traits, if it is sideroxylon, Red Ironbark, as i know down here, they are very common to fail at co-dom stem unions.
If the target rating is high, remove.
If tree retention is highly valued, aerial inspection with view to assessing suitability for cable bracing & possible canopy reduction.
Just quoted a failed one of this species the other day
I'll put up pics 2moro if you want an example for the client ekka.