Someone cheating
video
https://www.halowaypoint.com/en-us/games/halo-5-guardians/xbox-one/game-clips?page=1&gamertag=hazpz#ugc_halo-5-guardians_xbox-one_gameclip_hazpz_03e6ca8e-e2e2-46c5-8228-e5d5855ae9e3
If you’re looking to report players for potential cheating or modding, please head over to https://aka.ms/HaloPlayerReport and file a report against the player you encountered, video clips are extremely helpful in these cases.