Inspiration vs Stealing

I loved this Luxx shirt when I first saw it.  By a Canadian aboriginal Derek Jagodzinsky the medicine wheel and built in cape were visually appealing.  With no prices on his web site and only an in person store, I made my own version (a dyslexic version where the colours are mixed up).  Now the internet is full of designer inspired DIYs and I get a lot of inspiration from things I find online, but this shirt was pretty much a copy.  This got me thinking of whether this crossed the line between inspiration and stealing.  I only made it for myself and I am not going to profit from it but it still made me wonder where the line is?  What do you think?  Who is inspiring you?