Brandon Lee and Paul Walker come to mind. A year delay or more isn't rare, I don't think.
Even without incident, many movies with heavy special effects can take up to a year to finish the final draft. I kinda suspect it's by design. Get the studio hooked and ask for more money to increase the production values to match the acting.
River Phoenix had a role (Dark Blood) that he OD'd while filming, and it was put on hold, but then eventually finished and released 19 years later.
[delayed]