I was only seconds from the same lesson with my own boat. Approaching a draw bridge in early AM on the ICW, I pulled the throttle back to resist the 1-2 knot or so current going under the bridge and nearly stalled. I couldn't get any throttle at all, other than an idle in gear. Each time I attempted, the single Yanmar sputtered and nearly stalled. Heading for the bridge now broadside, hit the bow thruster (thanks God it worked this time) and spun the bow away from the bridge. With the stern now going under the bridge, I pushed the throttle forward to idle ahead. She stayed there for maybe 10 seconds or so with the stern under the bridge and my mast maybe 4 or 5 ft. from hitting, and she finally made some headway against the current, creeping back south on the ICW to the same anchorage I left (Boca Raton) about 200 yards away. While anchoring, the throttle came back fully and I was OK again. I checked everything, pulled and changed the filters, checked lines, tank, everything, but couldn't find the cause.
If this guy had the same thing happen to his starboard engine, it would explain everything on the video. Truth is, I'd have looked like a complete idiot banging around under that draw, and I couldn't have done anything to make me look more in control.
"I'd rather be happy than dignified".