I think that you should let it go. You don't know anything about the rate paid or the arrangements between the payer and the hotel.
The rate may have been ineligible for Honors credit.

Some excerpts from the Hilton Honors terms and conditions -

Qualification for all on-property Hilton Honors benefits, including complimentary Internet and MyWay benefits such as complimentary snacks and beverages, complimentary continental breakfast and space-available upgrades, requires a confirmed reservation made through one of the following channels: Any official direct Hilton hotel brand or Hilton Honors website (for example, Hilton Honors.com, Hilton.com, Hampton.com, etc.), Hilton Reservations & Customer Care phone line (1-800-4HONORS or local Hilton reservations office), Hilton Honors or Hilton mobile application, Directly at a hotel in the Hilton Portfolio, or Through an IATA accredited retail travel agent professional ("Travel Agent") booking through a Hilton channel or the following Global Distribution Systems: Amadeus, Apollo/Galileo, Worldspan and SABRE.

On-property benefits are not awarded in the following circumstances: Reservations booked through a non-Hilton-direct booking channel or a non-designated GDS, third party website or any other channel; Rates available on "opaque" websites where the hotel brand and specific hotel are not known until the booking is made, or Third party hotel packages or travel packages not booked through one of the eligible channels; Booking ineligible stays, (as defined in the Accrual of Points section) unless hotel contract has specific benefits included.

To earn Hilton Honors Points or credit toward tier status for hotel stays, a Member must be a registered, paying and staying guest at a participating hotel within the Hilton Portfolio and meet all of the conditions described herein.

Specifically excluded from the definition of "stay" are the following types of ineligible stays: wholesale/tour operator packages; contracted crew rates; travel agency discount rates; packages exclusively for casino player card holders; unauthorized Members staying on Go Hilton Team Member or Family & Friends Travel Rates; stays secured utilizing Hilton Grand Vacations Club and Hilton Club timeshare programs, Hilton Grand Vacations marketing packages with a sales presentation requirement; complimentary or barter rooms; NET Group rates; Series Group or IT Group rates; contracted Entertainment or Encore rates; third party websites bookings (irrespective of rate paid); and "opaque" channel bookings where the brand may or may not be known at the time of purchase.

A Member whose individual hotel bill is billed directly to a company and the Member is responsible for authorization for settlement at check-out is eligible for Hilton Honors Points as described herein. However, group master-billing arrangements where charges for multiple rooms are placed on one hotel bill and billed to a company or common address or settled at check-out by one individual are not eligible for Hilton Honors Points.