presence of the trait is enough; don't need to check a legacy flag too.

OpenRa.Game/Traits/SquishByTank.cs

@@ -0,0 +1,36 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using OpenRa.Game.GameRules;
+
+namespace OpenRa.Game.Traits
+{
+	class SquishByTank : ICrushable
+	{
+		readonly Actor self;
+		public SquishByTank(Actor self)
+		{
+			this.self = self;
+		}
+
+		public void OnCrush(Actor crusher)
+		{
+			self.InflictDamage(crusher, self.Health, Rules.WarheadInfo["Crush"]);
+		}
+		
+		public bool IsPathableCrush(UnitMovementType umt, Player player)
+		{
+			return IsCrushableBy(umt, player);
+		}
+		
+		public bool IsCrushableBy(UnitMovementType umt, Player player)
+		{
+			if (player == Game.LocalPlayer) return false;
+			switch (umt)
+			{
+				case UnitMovementType.Track: return true;
+				default: return false;
+			}
+		}
+	}
+}