Subsidence or Wall Ties Causing Cracks? All manner of questions and solutions to problems and issues surrounding the subject of brickwork, blockwork and stonework

[Maimee]

I'm interested in buying a house but it's got stepped cracks in the mortar above the windows and the 1st row of roof tiles seem to have dropped. After research I think it could either be wall ties or subsidence. If it's the latter then I'm going to walk away. I asked the owner about it and she said "the lintels had been checked and they're ok"! Before spending £500 on a surveyor I was hoping someone might be able to advise if it's likely to be subsidence. I've attached some photos of the cracks and roof tiles.Any advice would be greatly appreciated.