If you haven't installed the oven in your home with these brackets present, you may want to take a look to make sure that you have them. Just by taking a flashlight one can look in the back of your range to see if there are anti-tip brackets present. These brackets could be attached to the bottom legs of the oven or screwed to the wall behind the range.
The fact that they are present though, doesn't ensure that they will stop the oven from tipping. That's why it would be a good idea to have someone qualified to inspect their installation.
Yes just resting a thanksgiving dinner on an open door of the oven, a small child standing on the open door to check the stove, or a person resting on an open door while cleaning would be enough to tip an oven that doesn't have anti-tip brackets properly installed.
If you have any further questions, feel free to contact us.