This is an example how your bag made it from VA check-in counter at JFK to the baggage belt at LHR:
- VA employee checks the bag in
- the bag is screened by TSA. Screening takes place in an very open area at T1 and everybody can see what is going on - it would be very naive for an TSA employee to open the bag and steal an item from there.
- the bag goes under the terminal where it gets loaded onto the aircraft by VA ramp agents(they may be service contracted company employees)
- at LHR the bag gets unloaded by ramp agents and forwarded to the baggage belt for pick up.
As you see there are various steps where the bag can be opened and items stoled from there. Where this happened, it is very hard to guess.
Personally(not to blame you) I would not put expensive stuff in the checked-in bags. Or if I do , I will purchase an additional insurance for that.
This is an example how your