Yes, it matters to me a lot. Indeed it's vital.. I do try not to assume and one of the first questions I will ask is why.. Mainly I would always want to understand and to give the person a chance to explain.. Perhaps it wasn't what I thought... perhaps there are mitigating circumstances... I would always want to give people that opportunity and benefit of doubt..
Sadly most of the time the person knew exactly what they were doing and did it to hurt. or they didn't expect to get caught.. so questioning and seeking an explanation isn't exactly welcome.. But I would still prefer to give them that chance.