Some smaller birds, who are flighted but don’t usually fly, can get scared/panic and end up a bit hypoglycemic (low blood sugar) as direct result from an intense burst of flight. Usually this comes from a shock or sudden scare immediately preceding the flight. The bird lands and is then wobbly and unstable. Birds have rather large hearts in comparison to their bodies, and at rest have a higher blood pressure than you might think. So when a high stress, high activity occurs, the bird may develop an acutely changing pulse and glucose level due to the sudden increase in blood pressure. This then can manifest as if it looks like the bird is heaving for breath or short of breath and is weak or wobbly. They may even rest with their keel bone downwards. In my experience with this scenario, the bird does not ever lose consciousness or bowel, and there are no real jerking movements. The wings can be raised as if the bird feels over warm and there may be a shivering tremor present that quickly subsides. Many birds who do exhibit this are perhaps a bit overweight or even obese, and unaccustomed to flight although it can happen to fit birds as well. The symptoms go away as quickly as they came on in an otherwise healthy bird, although they are noticeably hungry and thirsty after an event like this.
If there were moments of intense specific jerking motions, such as outstretched clenched feet rapidly moving or even a brief loss of consciousness, then yes I would worry over possible stress related seizure activity.
It’s my experience that activity related (high stress event) seizures are not managed so much with medication, as prevention. Tiels and budgies are known to be vulnerable for seizing due to acute stress (like traveling or a vet visit) and so all avenues would be attempted to minimize stress on them as seizure prevention vs daily medication. This isn’t to say you shouldn’t seek medical help for your GC if you’re worried- but if the seizures are stress induced, there isn’t much able to be done about it. Blood testing can confirm the seizures are not related to dehydration or organ impairment, but testing won’t be able to tell you if your bird is at risk for more or when/where the next one would happen. Many stress seizure prone birds live long healthy lives with good management. And, if seizures ever do cross into the realm of uncontrolled and they happen without a precipitating event- that’s when medications can be explored and most birds respond well to them.