There was an hour delay before we boarded, followed by a “technical issue” when we pulled away from the gate which resulted in us having to go back to the gate to test an engine and then because our departure was so late (about 3 1/2 hours behind schedule at this point), we had to take a different (longer) route to get back to Canada, so, the whole trip took about 17 hours door to door. The crew did their best to manage the delay with a very full flight, so, kudos to them but it did make for a fairly stressful end of my trip as I was trying to figure out how to get home on board when I realised that there was an engine problem and we might be deplaned.