Del great question,
There will always be many of answers to your question. But here's my opinion.

Drift fishing is the #1 tactic you can use on steelhead especially when it's done to perfection. Likely the gentleman that fished that tailout was a highly advanced drift fisherman with great bait. Drift fishing, when done properly always has you in contact with the bottom and as you know that's where steelhead lay. When bobber fishing you may not see the slot change 2 feet in depth but with a bobber you are at a steady depth, and always a steady speed that is the speed of the current. You can alter driftfishing speeds by adding lead or reducing lead.

But, with excellent bait, it's hard not to catch a steelhead if presented well if one's there. Who know's those fish might have just moved up as you were talking and moved.
Keith