Thanks to Gaetano for highlighting which is something I hadn’t noticed before. In Zzap 64’s review of 19 Boot Camp Part 1, it seems they either reviewed an earlier build of the game, or they used screenshots provided/from a preview (taken some time before).
The shots are clearly different to the final game, with the assault course showing a hi-res layered main character, and a far more complex climbing frame. The shooting gallery part is different too – with a more simplistic zoomed target viewer.
Contributor Alex Edge mentioned in the comments that John Menzies (coder of Traz) had written the initial game, before leaving Cascade, where Joe Booth and Mark Greenshields took over to complete the game.