Have not seen any with shotgun pellets for sometime, it used to be quite common in Roe when driving them to shotguns was still legal in the 60s 70s Roe were seen as nothing more than vermin maybe more so here in the north
it was common practise for estates to organise Roe drives after the game season was finished, Roe were also quite often shot on walked up days.
In actual fact a shotgun can be quite effective at killing Roe in the right hands, the trouble with a lot of these Roe drives was the experience of those involved, while you had the keepers who knew what they were doing, tenant
farmers were often invited, as were people who might have helped out on shoot days beaters etc.
To be effective on Roe and avoid wounding the shot needs to be taken at very close range, no more than about 15 yards, and I have seen shots taken at double that range by the inexperienced.
Thankfully by the late 60s European sportsmen began to show an interest in coming to the UK to stalk Roe bucks
and estates began to realise there was a potential income to be made from letting Roe stalking and the practise of driving went into decline, eventually changes in the law would make using a shotgun all but illegal except in certain circumstances.
Jimbo while I have heard of the practise you mention, I think its more likely to be poor marksmanship at too great a range, I would imagine they have been trying to shoot them in the back of the neck as they ran off, possibly on a walked up type shoot, again the back of the neck shot is an effective shot, but you need to be close.
There is provision in law for shotgun use on deer in certain circumstances, hopefully most people will never need to use one, IMO the restrictions on shotgun use was one of the best acts ever in deer legislation.