And a spectacular own goal for Boeing that they deserved so much :D
Development costs doubled from 2 billion to 4 billion. Then when they went well over 5 billion and the federal government + Quebec had to bail them out to the tune of 1.5+ billion. Even without Boeing, had Airbus not stepped in, it's unlikely the CS100 would have succeeded. European buyers had already started to cancel orders seeing the debacle unfold.
Despite having many orders on the books, banks refused to lend to Bombardier because they expected them to make a loss on the airplane.
So yeah, screw Boeing who played really dirty and Trump helped them (the tariffs were reversed a year later when a more independent body reviewed them). But had Bombardier not been in a massive financial hole this wouldn't have mattered.
Boeing tried to screw Canada's Bombardier out of the C series aircraft by getting the US Gov to throw on tariffs for an aircraft they had no competitor for. Everything was already done AFAIK that point too; certifications, and everything, the plane was entering into production to fufill US airline orders. It cost $1.3 billion Canadian to develop the plane.
I suspect Boeing thought that'd be the end of it. Airbus had other ideas. They got the whole Bombardier C series aircraft for about $550 million and opened an assembly plant in Alabama in Mobile, about 350 miles from Boeing's assembly plant in Huntsville. Along with the orders from US airlines (I think for 130 aircraft). No more tariffs because these planes are now US made.
As a Canadian it stings a little, but I can't help but cackle at the fact that Boeing execs handed their one major competitor several billion in revenue on a silver platter. And Boeing will need years if not decades to come up with a competitor.
So from Canada: Get fucked sideways Boeing.