Yes - but much the same as some other electrical devices in the house - if the boiler now works OK and the RCD does not trip then it was something else.
As for the fumes you may have a different problem - consider a Carbon Monoxide detector for your own safety.
The "venting" of the boiler will have no affect on the RCD.
When you were away some electrical devices will have continued to operate and switch themselves off and on - Boiler (presumably you left it continuing to operate) Fridge & Freezer - not much else uless you left with the dishwasher still running - or a dryer - or a washing machine.
There is a very remote possibility that the RCD itself is defective - but I would doubt it.
There is also the possibility that two appliances - each with a very small amount of earth leakage and nothing to worry about and not at all dangerous and not enough to trip the RCD - operated by chance at the same instant - and that the combined leakage of these two tripped your RCD.
Peccavi
August 2010