Guys, Why would he pretend to be busy?

So i am seriously busy and have a lot on this week and texted a guy i was supposed to be catching up with and said i will let him know when i am next free. A day before i was going to be away, he texts me to let me know that he is not sure if he arranged to see me but that he is busy (gave a reason) and so will be tied up next few days...
I can't think of one logical reason why a guy would do this, i mean its not like i made a huge deal out of going away so he had no need to feel defensive. I am the one who texts all the time, so he had no reason to feel silly. The answer is probably obvious to a guy but i find it slightly odd being that i am the one who makes an effort as a friend a lot not the other way round?
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+1 y
Also just to add I told him I was busy first, so wasn't sure if this makes a difference?
Guys, Why would he pretend to be busy?
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