There's always two different ways to see this really.
Either you can see it this way,
FH+ was made by TLK4EVER and he can in no way possible control all the maps and other content that is made and changed around. Going just onto your map alone saying you are not allowed to use some textures because it was for FH+ isn't exactly the wisest choice since NO ONE gets anything out of it. FH+ and FH is pretty much the same game, and if simba is the owner of the textures he shouldn't really bother, if he for some reason isn't, then he would've been doing something far worse than you could ever do with the textures in that map, unless he got admittance to use these textures from either a friend or free for use.
Or the more complicated way that doesn't really work in general since it happens everywhere,
You are not allowed to use ANYTHING at all without permission, if you know you didn't make these textures you must ask TLK4EVER for his permission to use them, and if not make sure the sources of the textures were free for use, doesn't matter if you give credit or not, still not your work.
The first one is pretty much how it works, and the 2nd one is pretty much what the actual copyright rules says.
Something a lot of people seem to misunderstand is that you cannot live 100% by the rules, and neither can you ignore them all together since you must keep a few things in mind. I spose each and everyone has to find out when there's musts, and when you can make exceptions.
Copyright rules is a serious subject though, but if you were not able to work around it or everyone would've followed them by 100% all the time, sites like youtube, tumblr, myspace, maybe even facebook would not exist or be popular. Whole internet would not be known as it is.
Hope this clears it up a bit.
//Personal view,
No, I do not think you will get in any trouble.