Is it the same lurchers? If so, the breed is irrelevant and it's just irresponsible dog ownership on the part of the other owner.
Lurchers do have a strange way of playing - they tend to grab the backs of necks and nip bottoms or tails, this is how they play with each other and is entirely play - not aggression. I am very careful who I allow my two to play with, as I realise this is probably not going to be appreciated by many other owners (although to be honest, most dogs do seem to 'get' the game and thoroughly enjoy a good game of Lurcher chase) and they have each other to chase if they want to play Lurchery games.
That said, mine would never be allowed to approach a dog that was on the lead and I always try to check with owners when the other dog is off-lead as well. Which is why I think it sounds more a problem with irresponsible owners than anything else.
Fwiw, it's Labradors around here. There are so many poorly trained Labs whose owners ignore them, stand on the other side of the park and let them charge up to on-lead dogs and leap on them, that my own Lurcher ended up fear aggressive as a result of it happening for successive days on walks when he was only just allowed to go down on the ground as a pup. He's 15 months old now and we are still dealing with the fall-out from those irresponsible dog owners behaviour.
Despite this, I don't believe this is a 'Labrador problem' - again it's just irresponsible dog owners and there just happens to be a proliferation of Labradors around here - so when there's a problem, there's a high probability that it will involve one.