In presenting this equitable defense, two notes are in order.
First, this is a separate defense to the clean hands doctrine, though closely related.
With clean hands, one needs to show some bad conduct on the part of the person seeking to invoke a court's equitable jurisdiction.
The threshold for the equitable defense of "he who seeks equity, must do equity", actually requires less. All that must really be shown is that the plaintiff hasn't acted fairly. This could be shown in respect of assignment forgery, fabrication of documents, perjured affidavits, but could possibly even be something as basic as misconduct in respect of a HAMP modification (perpetually losing the borrower's paperwork while accepting government funds for entertaining the HAMP application).
I have never seen a single foreclosure case nationally where a defendant has prevailed on this doctrine, so showing the precise boundaries is difficult. Suffice it to say that a court sitting in equity has a great deal of discretion to do justice.
It should also be noted that an equitable defense of this sort is only applicable to the count of the typical two count complaint pertaining to the foreclosure of the subject property. The first count of most judicial foreclosure complaints is a count pertaining to default under the note.
The claim under the first count is typically an action at law, while the second count as to foreclosure is an action in equity. The equitable defenses would usually only apply to the action at equity.
Prevailing on any of the equitable defenses in a judicial foreclosure action could result in a mixed judgment against a defendant where the plaintiff obtains a judgment at law on the note, but is denied the requested remedy of foreclosure as to the subject property in the second count. The owner might then retain possession of the subject property, but be liable for an unsecured judgment. In places where strong homestead laws prevail, a borrower might very well be able to subsequently discharge the unsecured judgment in bankruptcy, while keeping the subject property.
Compared to all of the nonsense being peddled by swindlers and debt elimination scam artists, this defense has a sound foundation in over six centuries of equity jurisprudence. The key is persuading the court of the inherent inequities perpetrated by the plaintiff. This isn't going to be easy, but like all arguments, the argument is waived unless expressly plead.
You will usually not find this argument within any of the pleadings of the mediocre foreclosure defense lawyers practicing in Florida.
Mr. Roper has no less than a leading Justice of the U.S. Supreme Courts and centuries of jurisprudence in support of his argument. The Florida foreclosure defense lawyers just seem to make up weak arguments as they go and are both too lazy to research the law or even to read and apply Mr. Roper's insightful posts.