In the opening scene, their shadows fall behind them while they face the rainbow in front of them. A rainbow is formed by the sun's light reflected by water droplets in the atmosphere. The sun should be behind the observers in a direction opposite the rainbow, so their shadows should be in front of them.
The students plant seeds in flower boxes. Some few weeks later, these seeds have grown into blooming tulips. In the first place, that is way too fast. Tulips can grow from seed, but will take about 3 years to flower.
When Paul serenades his wife in the park, he plays the guitar left handedly but the guitar is strung in the normal fashion for a right handed person.
Supposed to be a city in the US, but is obvious that it is Vancouver, BC. The bike ride and aquarium are in Stanley Park and the lighthouse is along the seawall walk.
Hospital jacket in waiting room is left behind on a chair.