Grab and Throw Script changes velocity without reason

When I release the selected GameObject, the object flies off in a completely different direction. The log seems to suggest that the velocity value itself is completely different from what it was released at.

Here's my Grab.cs: using System.Collections; using System.Collections.Generic; using UnityEngine;

 public class Grab : MonoBehaviour {
 
     private GameObject releasedObj;
     private GameObject selectedObj;
     private GameObject grabbableEnemy;
     public Transform gripTransform;
     private SteamVR_TrackedObject trackedObject;
     private SteamVR_Controller.Device _controllerDevice;
     private SteamVR_TrackedController _controller;
 
     private Vector3[] positions = new Vector3[2]; // positions[0] last frame, positions[1] this frame;
 
     private bool gripGripped;
 
     void Awake()
     {
         trackedObject = GetComponent<SteamVR_TrackedObject>();
     }
 
     // Use this for initialization
     void Start () {
         _controllerDevice = SteamVR_Controller.Input((int)trackedObject.index);
         _controller = GetComponent<SteamVR_TrackedController>();
         _controller.Gripped += HandleGripGripped;
         _controller.Ungripped += HandleGripUngripped;
         positions[0] = Vector3.zero;
         positions[1] = Vector3.zero;
 
         releasedObj = null;
         selectedObj = null;
         grabbableEnemy = null;
         gripGripped = false;
     }
 
     // Update is called once per frame
     void FixedUpdate () {
         if (selectedObj)
         {
             Debug.Log("Updating velocity");
             positions[0] = positions[1];
             positions[1] = selectedObj.transform.position;
         }
        
         if (releasedObj)
         {
             Debug.Log("Released V: " + releasedObj.GetComponent<Rigidbody>().velocity);
         }
         if (_controllerDevice.GetPressDown(SteamVR_Controller.ButtonMask.Grip))
         {
             Debug.Log("Gripped");
             if (grabbableEnemy)
             {
                 Debug.Log("Grab sequence begins");
                 selectedObj = grabbableEnemy;
                 Debug.Log(selectedObj.name);
                 selectedObj.transform.position = gripTransform.position;
                 var joint = gameObject.AddComponent<FixedJoint>();
                 joint.connectedBody = selectedObj.GetComponent<Rigidbody>();
             }
         }
         if (_controllerDevice.GetPressUp(SteamVR_Controller.ButtonMask.Grip))
         {
             Debug.Log("Ungripped");
             if (gameObject.GetComponent<FixedJoint>() && selectedObj)
             {
                 Debug.Log("Launch sequence begins");
                 Vector3 velocity = (positions[1] - positions[0]) / Time.deltaTime;
                 foreach (FixedJoint joint in gameObject.GetComponents<FixedJoint>()) {
                     Destroy(joint);
                     //Debug.Log("Fixed Joint value: " + joint + " & Component value: " + gameObject.GetComponent<FixedJoint>());
                 }
                 releasedObj = GameObject.Instantiate(selectedObj);
                 releasedObj.GetComponent<Rigidbody>().velocity = velocity;
                 Debug.Log("Released @ release: " + releasedObj.GetComponent<Rigidbody>().velocity);
 
                 // For garbage collection?
                 Destroy(selectedObj);      
             }
         }
     }
 
     private void LateUpdate()
     {
         //if (!_controllerDevice.GetPress(SteamVR_Controller.ButtonMask.Grip))
         //    selectedObj = null;
     }
 
     private void HandleGripGripped(object sender, ClickedEventArgs e)
     {
         gripGripped = true;
        
     }
 
     private void HandleGripUngripped(object sender, ClickedEventArgs e)
     {
         gripGripped = false;
     }
 
     private void OnTriggerStay(Collider other)
     {
         Debug.Log("Triggered");
         if (other.gameObject.tag == "Enemy")
         {
             grabbableEnemy = other.gameObject;
         }
     }
 
     private void OnTriggerExit(Collider other)
     {
         grabbableEnemy = null;
     }
 }
 

Here's my Log:

 Triggered
 UnityEngine.Debug:Log(Object)
 Grab:OnTriggerStay(Collider) (at Assets/Grab.cs:106)
 Gripped
 UnityEngine.Debug:Log(Object)
 Grab:FixedUpdate() (at Assets/Grab.cs:54)
 Grab sequence begins
 UnityEngine.Debug:Log(Object)
 Grab:FixedUpdate() (at Assets/Grab.cs:57)
 Sphere (The name of grabbed)
 UnityEngine.Debug:Log(Object)
 Grab:FixedUpdate() (at Assets/Grab.cs:59)
 Updating velocity
 UnityEngine.Debug:Log(Object)
 Grab:FixedUpdate() (at Assets/Grab.cs:43)
 Ungripped
 UnityEngine.Debug:Log(Object)
 Grab:FixedUpdate() (at Assets/Grab.cs:67)
 Launch sequence begins
 UnityEngine.Debug:Log(Object)
 Grab:FixedUpdate() (at Assets/Grab.cs:70)
 (-3.1, 4.0, -1.6)
 UnityEngine.Debug:Log(Object)
 Grab:FixedUpdate() (at Assets/Grab.cs:76)
 Released @ release: (-3.1, 4.0, -1.6)
 UnityEngine.Debug:Log(Object)
 Grab:FixedUpdate() (at Assets/Grab.cs:79)
 ----------------- H E R E ---------------------------
 Released V: (11.9, 3.7, -1.7)
 UnityEngine.Debug:Log(Object)
 Grab:FixedUpdate() (at Assets/Grab.cs:50)
 Released V: (11.9, 3.5, -1.7)
 UnityEngine.Debug:Log(Object)
 Grab:FixedUpdate() (at Assets/Grab.cs:50)
 Released V: (11.9, 3.4, -1.7)
 UnityEngine.Debug:Log(Object)
 Grab:FixedUpdate() (at Assets/Grab.cs:50)
 Released V: (11.9, 3.3, -1.7)
 UnityEngine.Debug:Log(Object)
 Grab:FixedUpdate() (at Assets/Grab.cs:50)
 ...etc