He has advised on disputes including claims by Alcoa against Harriet Joint Venture (HJV) partners for damages for interruption to gas supply arising out of the Varanus Island explosion and the prosecution of HJV parties for alleged failure to maintain gas pipelines.

Lockhart has advised commercial clients on competition, access and regulatory matters. He advised Newmont on all of its access disputes in relation to the WA electricity grid.

He is the author of The Law of Misleading or Deceptive Conduct and has lectured at the University of Western Australia (UWA) on the topic as well as on the topics of contract law, intellectual property and competition law.

Lockhart also taught International Commercial Arbitration and International Business Law at the UWA Graduate School of Management.