2015 WRX Overheated?

Hey Guys,

So the other day I noticed some coolant on the ground. Come to find out the top radiator hose had a tiny hole in it and coolant was splashing all over the place. The night I found that out the car had NOT overheated or anything I just happened to noticed it. So I let the car sit for a few days until I got the part. Swapped it out tonight and looked at the coolant reservoir and it was at the low mark so I topped it off to full (reservoir only). Turned the car let it heat up and drove it down the street. Everything was fine and as soon as I floored it the temperature gauge went from the middle to red and the warning light started to flash. It was not gradual increase in the temperature gauge but instant jump. So I pulled right over and checked under the hood. There was no leaks or anything and the hose was fine and there was coolant in the reservoir. I waited 10 minutes or so and I added more distilled water to the actual radiator and turned the car on without a problem. Drove it around and its not overheating. I am just wondering what happened since there was no gradual overheating, in a matter of one second the temperature gauge went from being in the middle to fully in the red. Do you guys thing that the thermostat opened and there was not enough coolant so the temperature reading jumped to the red? Any ideas would be great

Thanks,
~fly