We really have no way to know all the details. I’m involved in these types of projects all the time, and a painter would normally be a subcontractor...for all we know Trump’s company paid the general, but for some reason the general hasn’t been timely in paying subs.
Also a good point. Subs would rather post a lien on a property than sue the general, knowing that the client has more leverage on the contractor than the sub does.