Found a good slideshow on how the bankruptcy court works -
In rendering its decision, the Supreme Court relied upon its decision in Katchen v. Landy which " turned . . . on the bankruptcy court,s having ' actual or constructive possession ' of the bankruptcy estate, . . . and its power and obligation to consider objections by the trustee in deciding whether to allow claims against the estate. " The Supreme Court interpreted its prior decisions in Schoenthal and Katchen as holding that a creditor's Seventh Amendment jury trial right depended on whether the creditor had filed a proof of claim. "' By presenting their claims [the creditors] subjected themselves to all the consequences that attach to an appearance . . . . '"
As Katchen makes clear . . . by submitting a claim against the bankruptcy estate, creditors subject themselves to the court's equitable power to disallow those claims, even though the debtor's opposing counterclaims are legal in nature and the Seventh Amendment would have entitled creditors to a jury trial had they not tendered claims against the estate.