Just after Isabeau falls from the abbey tower and turns into Ladyhawke, a soldier emerges onto the roof of the tower and questions Phillipe. An arrow is then fired (by Navarre) into the left-side of the soldier. However, he initially grabs at his right-side. After a couple of seconds he correctly grabs at his left-side, before falling off the tower.
In the days before ubiquitous digital technology, the majority of visual effects in film were "practical" effects using stuntmen and props on wires, springboards, flash-pots, et cetera. In "Ladyhawke" (which was decidedly on the low-end of visual effects budgets), one of the most dangerous practical effects is seen when Matthew Broderick and Rutger Hauer have a heated discussion in the woods and seem about to part company. As Broderick turns to leave, Hauer's 53" longsword sizzles past the boy's left shoulder and embeds in a tree trunk, to Broderick's horror. In fact, the steel sword was real and hurtled to its target on a guide-wire, barely 8 inches from Broderick's back. If you slow-advance the scene, you can see the sword actually changing trajectory in-flight, it was so unstable. The sword came up in a Hollywood memorabilia auction in 2002 but was not sold. http://www.icollector.com/Rutger-Hauer-prop-special-effects-sword-from-Ladyhawke_i169815.