I’ve seen it stated more than once than when multi-manning with a digital tachograph, the first 45 minutes of POA counts as break. I have seen it explained that this is because the tachograph cannot record Break on the card in Slot 2 while the vehicle is in motion. I can understand this argument.
But is this stated in any official document? The reason I ask is that I have been “awarded” two infringements for last week, when I was crewed with another driver and sitting in the passenger seat. They are only WTD infringements, but my employer seems to be getting slightly agitated about it, so I would like to be able to refute these alleged infringements. I can’t see any mention of it in the Regs.
I think this might cover it? look under example 1.
where it states that when travelling in a multi-manned vehicle, the first 45 minutes of a period of availability is considered as a qualifying driving break for the purpose of the 4½ hours driving regulation. Therefore, it is possible for the driver to undertake his driving, swap seats and take his 45-minute break, under the PoA mode, within a moving vehicle,
Great! Thanks for the pointer. Managed to find it in my copy of the GV262 which I can now wave under the nose of our “driver trainer” 
(Page 28 of the 2011 edition, for anyone who may be interested)
Multi-manning – second driver record
Some analogue equipment and all digital tachographs will automatically record all time spent as a second driver when the vehicle is in motion as a period of availability and do not allow the mode to be changed to either ‘break’ or ‘other work’. Provided the second driver is not required to carry out any work during this time, enforcement authorities will accept the first 45 minutes of this time as a break from driving.
Looks like youv found the writing bit.
A word of advice, IF your running in france, the gendarmerie dont like to accept the first 45 mins as a break. If you can, and time permits, take a proper 45 once youv both driven 41/2 hours each.
muckles:
I think this might cover it? look under example 1.
Periods of availability explained | Croner-i
where it states that when travelling in a multi-manned vehicle, the first 45 minutes of a period of availability is considered as a qualifying driving break for the purpose of the 4½ hours driving regulation. Therefore, it is possible for the driver to undertake his driving, swap seats and take his 45-minute break, under the PoA mode, within a moving vehicle,
Am I the only one who finds this choice of wording slightly unfortunate? 
Concretejim:
Looks like youv found the writing bit.
A word of advice, IF your running in france, the gendarmerie dont like to accept the first 45 mins as a break. If you can, and time permits, take a proper 45 once youv both driven 41/2 hours each.
Thanks for that - I was aware that it was only really applicable to the UK enforcement authorities. Fortunately there is no chance I’ll be driving a truck anywhere outside the UK.