A properly latched top can not come open. If the latch mechansim is engaged unless there is a failure, the force required to overcome the latching mechanism can not be generated due to strictly aero forces.
Take a look at the latch hook. Many of us have improperly stowed the top in the trunk and bent the latching hook. The proper way is to unlatch the top and store it in the trunk. If you unlatch the top then move the top to the rear AND return the latch handle to the locked position, when you seat the top in the trunk, the latch hook will be exposed. When you close the trunk, the latch hook will be deformed.
In my case, I found this out when I went to put the top up and the hook would not engage. At all. When I slammed the trunk with the latch hook "out" it bent the crap out of it so the lock would not engage at all.
It is remotely possible that your hook was bent enough to compromise its latching strength but not so much to cause it to fail to engage.
Take a careful look at the hook and see if it is straight or slightly bent upward. This might explain why it failed at speed.
If the guide pins are not in the holes in the windshield frame, the hook will not engage. It is too short to mate with the locking pin in the windshield frame unless the guide pins are at least partially into their respective holes.
Given that the top is now bent, you have some options.
A new GM top is $3000 plus installation. I believe that they are still in stock so its possible to get one.
There are several people who have "new - used" tops. When people went racing in 2006 and 2007, the rules called for a "hard" top, so a lot of racers pulled their top assemblies and after a while sold them pretty cheaply. I bought one for $400 plus $200 shipping. Its in my basement. There are at least 5 others on this forum and probably a like number on the Sol forum who bought spares as well. You might induce one of them to sell you their spare. Heck, maybe even their current top if they want to go to their backup for any reason.
You can find a good parts guy and he can probably find you a used / recycled top at a recycle yard for probably the same cost. ~$500 to $1000 if you spend time looking.
Alternatively, take your top out of the car - its four bolts and the whole assembly comes out. Pretty straightforward. Put it on a bench and start inspecting the bits and pieces to assess the damage. Some deformed parts might be repairable. Many of the parts are available in GM inventory but can get fairley expensive. I have seen several different assemblies that make up the top listed in inventory.
Given that its winter, I would pull the top and check it out in detail first and then decide on how you want to proceed. You might also find a local top shop that will be willing to fix it for you for a lot less than buying a new one.