What makes you think his intentions were to hurt sponsors as opposed to simply saving money and making something himself? His original post clearly stated he couldn't drop the money, so he made one himself.
Personally, I don't believe 4x4 will even get a design patent on the bracket. So until he does, point is moot. At best he might be granted a utility patent.
Like others have stated, his attitude and approach will likely cost 4x4's more in lost sales on lighting than he ever would have made on...
OP didn't "give out the information" he came on here, (a community built around members discussing and helping members modify vehicles) and asked if it was bad form. 4x4 responded poorly as he often does, threw out some bullshit threat in an attempt to intimidate the OP.
Not a fan of him or his posts in any of the threads I've read tbh... I wasn't planning on buying anything from him to begin with and DEFINITELY won't be now.
This thread made me chuckle and cringe all in one, numerous times...
As for your patent protection, good luck on that.
A: You don't actually have a patent yet, you'll need to wait until your patent is approved by the Patent Office before you can take any action other than your lawyer sending...