In 2004-5 I worked in bus lane enforcement at TfL.
It was specifically hammered out to us during our training that any drivers seen entering bus lanes to avoid emergency vehicles were not to be fined. At the end of each day all of our 'contraventions' would also be reviewed by a more senior member of staff, and if we'd fined anyone accidentally for making way for emergency vehicles they were then cancelled, before even requesting the data from the DVLA. Additionally at appeal anyone found avoiding an emergency vehicle would have their fine cancelled.
So either the policy has changed in the past ten years, or your brother's anecdote (assuming it was a TfL camera - we also took on work for other London boroughs on a contractual basis) was a very very very unusual and unfortunate case.
I suspect the problem is that once it's in the system, they are very unwilling to reveal what the usual policy is, so will fight the appeal, as otherwise that would mean another loophole. I would agree it's sensible to use common sense here, though.
In 2004-5 I worked in bus lane enforcement at TfL.
It was specifically hammered out to us during our training that any drivers seen entering bus lanes to avoid emergency vehicles were not to be fined. At the end of each day all of our 'contraventions' would also be reviewed by a more senior member of staff, and if we'd fined anyone accidentally for making way for emergency vehicles they were then cancelled, before even requesting the data from the DVLA. Additionally at appeal anyone found avoiding an emergency vehicle would have their fine cancelled.
So either the policy has changed in the past ten years, or your brother's anecdote (assuming it was a TfL camera - we also took on work for other London boroughs on a contractual basis) was a very very very unusual and unfortunate case.