I’d say it was an obvious solution to the problem, and well done that driver.
I know I’ve been in a similar situation at least once where a police detour sent me towards a bridge on a tiny country road that was right on the cusp of bridge height & vehicle height, and I told myself if I found I couldn’t go under I would have done that. If anything had come of it I would have just told the police it was their faulty detour that forced me to do it.