The plume coming from the SU-27 didn’t look like an afterburner light to me. Usually, when an afterburner lights you see only the flame extending from the nozzle (which may not be obvious in full daylight). This looks like a fuel dump, which is what was reported by the U.S. European Command. You can probably dump fuel very rapidly by turning on fuel flow to the afterburner without activating the igniter. (The heat of a turbofan engine’s exhaust is insufficient to ignite the fuel by itself, as was explained the in the post here on 2022-07-01, “Adding an Afterburner to Your Home-Built Jet Engine”.)
The ability to control afterburner fuel flow and igniter separately is what allows the “dump-and-burn” maneuver so popular with airshow audiences.
At the very end of the video, it does appear that one of the blades of the propeller has been damaged, indicating some kind of impact.