King Air 300 pilot reported the right engine rolled back after takeoff resulting in momentary loss of aircraft control.

Narrative

I was to ferry our King Air 300 from ZZZ to ZZZ1. A VFR flight conducted at night. On departure just as I got airborne and reached for the landing gear handle; the right engine rolled back (as it does in many King Airs when you release the throttle) and the aircraft began to roll to the right since I was slow and draggy as the landing gear was coming up. The engine did not fail; the power lever retarded to almost the idle position. I leveled the wings of the aircraft and pushed the throttle up to full power and accelerated to continue the climb. My flight path drifted off to the right side of the runway and I overflew the taxiway and a couple hangars as I corrected the flight path. I believe there were some people in the vicinity of the hangars as I saw some cars and movement when I taxied out. I am submitting this report because I don't know if the altitude / flight path startled them or not during my correction. After the aircraft was back on the climb schedule and any other problems were ruled out; I began a climbing left turn and proceeded on the flight. There was at no time any danger to any persons or property but I want to be sure this is not seen as intentional or lead to any punitive actions for handling a aircraft induced flight path deviation from the norm. I fly into and out of both ZZZ and ZZZ1 very frequently and do not desire any spotlight shed on my actions. The problem with the aircraft is not engine related; only the loose power lever that does not tighten appropriately with the friction lock. The aircraft is in inspection now and the friction locks will be addressed.