Need advice tenant informed me they did a repair w/o approval

[Todd Mulholland]

I need a little advice here. I have a long term tenant who I inherited when I purchased the property he has always called us whenever there was an issue (A/C not working, Broken window, toilet not working etc) Well last night around 8:30 pm we received a call from him that he called a plumber to remove roots from the sewer line and wants us to pay the bill. Now we were out there in April with a plumber due to roots in the sewer line, the plumber and I were there for around 4 hours he ran a camera through the lines and cut out all the roots and then ran the camera through it again and the line was clear. In addition we removed the tree that had grown into the line. 

So here's my question sadly the lease we had our attorney draw up doesn't state that they must call us for repairs (however they always have in the past and we have always taken care of it within a day) but it does state they can't make any improvements or changes to the property without prior approval. He never attempted to contact us and said that around 2 weeks after we had the roots removed that the problem came back. So he's saying he has had some degree of issues with his toilet since mid April but he never bothered to contact us about it. Now 5 months later he just calls someone out there without calling us. Had he called us more than likely we could have had the same plumber come back at little to no cost. So would you reimburse the tenant for this? I haven't even seen the invoice yet and he didn't give us an amount. I'm kind of inclined not to pay it as if he called us like he has in the past as soon as he noticed the issue we could have taken care of it.

Any advice would be appreciated.