Technical Head gask and oil leak. Cause and effect?

[Cunto]

Just had an mot done and they said my head gasket has gone and needs skimming. I have an oil leak from the sump, quite a bad one, could this have caused it? If so, i will need to get that fixed as well. FYI there was a short period of time where i was running the car without oil or coolant caps on it. Would that have helped my gasket go?

 

[LanciaMad]

Just had an mot done and they said my head gasket has gone and needs skimming. I have an oil leak from the sump, quite a bad one, could this have caused it? If so, i will need to get that fixed as well. FYI there was a short period of time where i was running the car without oil or coolant caps on it. Would that have helped my gasket go?

Oil coming from sump maybe sump but could be cam cover gasket leaking which is a more common problem. How do the garage know your head gasket has gone?