when viewing how you died, there’s a chance that some of the enemy players show up as a pair of legs with a floating weapon
[edit] i’ve only witnissed this on pc MCC halo 4 kill cam {sitrec replay}
It’s much easier for the devs to collect info if you use the ticket system: https://insidersupport.halowaypoint.com/hc/en-us/articles/360039258572-How-to-Submit-a-Ticket 
Hi there, please make sure and file any bugs reports to the Insider Support site. Be sure to read the known issues list before reporting. Thank you
https://aka.ms/HaloSupportInsider