The way I heard it elsewhere (Google should help), Twitter/Elon actually had the necessary and correct permits (for using heavy machinery on the street/sidewalk and redirecting traffic around it).

Unfortunately, that detail was not correctly communicated to building security, who called the police believing there was no permit.

By the time the misunderstanding could be cleared up, the workers & heavy machinery had… “vacated premises” already, leaving the work in its half-finished state.