Bonanza 35
Air Traffic Control Fully Certified
Confusion
Deviation - Altitude Excursion From Assigned Altitude; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Human Factors; Procedure
A Bonanza 35 was inbound to HLN on V2. He was cleared to hold at SWEDD intersection. He acknowledged the holding instructions. He was instructed to hold at SWEDD South East as published EFC. ZLC Sector 12 called and advised the Bonanza 35 was well North of the airway and I told them I would check on it but he was probably setting up for the hold at SWEDD. The Bonanza 35 advised he was established in the hold at SWEDD. At that point I did not ask him if he was North of the airway. I was relieved of the position. During the brief relieving Controller was instructed that the Bonanza 35 was in the hold at SWEDD. The Bonanza 35 later had a altitude deviation and during a phone call to Management said he was never in the hold at SWEDD but rather just flew NE bound for blue sky. Lack of RADAR in HLN left me unable to monitor the Bonanza 35 to ensure he was flying the hold as instructed.  Better IFR training for the Bonanza 35 would have prevented the misunderstanding of how to fly a published hold.
HLN Controller described a confused holding event when a pilot issued holding instructions failed to enter hold as prescribed.