Fix Raw Gas Scan (#30120)

code/game/objects/items/devices/scanners.dm

@@ -712,22 +712,22 @@ SLIME SCANNER
  * Used in chat-based gas scans.
  */
 /proc/atmos_scan(mob/user, atom/target, silent = FALSE, print = TRUE, milla_turf_details = FALSE, detailed = FALSE)
-	var/datum/gas_mixture/gasmix
 	var/list/airs
 	var/list/milla = null
 	if(milla_turf_details && istype(target, /turf))
+		// This is one of the few times when it's OK to call MILLA directly, as we need more information than we normally keep, aren't trying to modify it, and don't need it to be synchronized with anything.
 		milla = new/list(MILLA_TILE_SIZE)
 		get_tile_atmos(target, milla)
-		gasmix = new()
-		gasmix.copy_from_milla(milla)
-		airs += gasmix
+
+		var/datum/gas_mixture/air = new()
+		air.copy_from_milla(milla)
+		airs = list(air)
 	else
-		gasmix = target.return_analyzable_air()
-		if(!istype(gasmix, /list))
-			gasmix = list(gasmix)
-		airs += gasmix
-		if(!gasmix)
+		airs = target.return_analyzable_air()
+		if(!airs)
 			return FALSE
+		if(!islist(airs))
+			airs = list(airs)
 
 	var/list/message = list()
 	if(!silent && isliving(user))