Haldol and torsades in hospitalized patients---do you always need continuous electocardiographic monitoring?

Here's what a review in The Journal of Hospital Medicine says (my italics):

While administration of IV haloperidol can be associated with QTP/TdP, this complication most often took place in the setting of concomitant risk factors. Importantly, the available data suggest that a total cumulative dose of IV haloperidol of less than 2 mg can safely be administered without ongoing electrocardiographic monitoring in patients without concomitant risk factors.

Considering the number of patients who get hypokalemic, hypomagnesemic or get other QT prolonging drugs (can you say Levaquin?) that may be a pretty select group. And given that you never know when you might reach that threshold of 2 mg, well...