The currentOp command (and the equivalent pseudocommand "inprog") incorrectly ignores any $near or $text predicates passed in as a filter. Instead, an error should be returned at parse time if these predicates are used.

See, for example:

> db.adminCommand("currentOp", {$text: {$search: "hello"}}).inprog.length
1  // Unexpected: no operations should match.
> db.adminCommand("currentOp", {a: {$near: [0, 0]}}).inprog.length
1  // Unexpected: no operations should match.

I believe that this behavior has existed since the introduction of the $text and $near predicates.