Thanks for the deserved knuckle rapping!
- not a problem, glad to help.
After maintenance, double check everything. I'm just a low-time PPL but I got my scare on my very first flying lesson. We flew in the back of another plane to a small strip where our plane had been painted, to collect it. Shiny new paint job (shabby jobs, but that's another story) and the paint shop had already removed all the masking tape... Except for the tape on the pitot/static mast.
Backpacker: Although I can understand your concerns, it is not feasible or necessary to double-check everything. We in the UK have had duplicate inspections for years covering stuff like flying controls, engine controls etc focusing on so-called vital points. VPs are those that, if they were to fail, would cause catastrophic loss. Until recently, EASA had no similar requirement.
EASA Part 145.A.65 requires as system for prevent errors due to simultaneous maintenance on safety critical systems. Part M (Continued Airworthiness) requires duplicate systems a la UK BCAR requirement for Part 145 and M. Subpart F organisations. I'm not sure how your certification system works for aircraft such as the 150 flying for hire - is it CAT? Probably is. You can specify a duplicate inspection on whatever you like in addition to VPs (and O2 seems like a good idea!!) but I know organisations that specify dupes for first aid kits and fire axes - not a good idea; you can dilute awareness if you over dupe.