Step Turn
If, however, you were impressing the onlookers with a needless climbout at Vx, you're flying at 64 kts - the the bang still happens at 50 feet. you push, and start going down. You will be well on your way down, as you attempt to accelerate to the desired 75 kts "best glide" speed.
The only time you need to climb a Vx would be to clear a close in obstacle once clear accelerate to Vy.
That said if the engine goes bang at 50ft in the conditions you described as long as the pilot is mentally prepared for the failure they are only approx. 30ft above the flare so its reasonable to accept a successful landing is achievable.
Using the same scenario with the failure at 100-200ft that could be a different outcome for the unprepared.