You were flying a VOR approach in the box, which made it an RNAV procedure, regardless of the procedure title. The FMC selected what it needed for sensors to fly the approach, but rest assured it was not merely VOR input: it was taking input from all sensors on that procedure in order to conduct the procedure, and whether it's titled as VOR or RNAV, it's still flown as a non-precision RNAV through the box. Because you had the altitude values in the legs page, and because your altitudes were set in the MCP, you had no need to re-cruise the box, especially if you were already in VNAV Path.

The only thing change to be made, and that's setting up the procedure, is if both the FAF and the prior fix are /A (above" altitudes, then the prior fix is best made a "hard" altitude. That wouldn't have changed the result in your case; you gave the FMC new guidance that was lower than the crossing fix. More importantly, you weren't just giving it another altitude, but changing the mode of the FMC.

Again, doesn't change the result. Pass the second ride and move on. You can't make the former failure go away, but you can put time and distance behind you, on a bed of successful employment and checkrides. Living well is the best revenge.