Is the strategy of pretexting an acceptable means in order to obtain critical information that will strengthen a company's internal control system?

Is the strategy of pretexting an acceptable means in order to obtain critical information that will strengthen a company's internal control system? The following legal advice was obtained on the subject by HP:

The committee was then advised by the committee's outside coun- sel that the use of pretexting at the time of the investigation was not generally unlawful (except with respect to financial institu- tions), but such counsel could not confirm that the techniques employed by the outside consult- ing firm and the party retained by that firm complied in all respects with applicable law