PUSH DOWN SHIFTER FOR REVERSE GEAR VS 6TH GEAR

[RYANS1404]

I just had my clutch replaced at 67k miles and after getting the veh back i found that in order for me to shift into 5th or 6th gear i have to push the shifter down and then put into gear. just like as if i were to shift into reverse. goes into gear with no grinding or problems, so im sure it has to do with somthing not being put back together properly but im not sure what restricts the shifter to go into gear with out pushing down first. how does it stop it from going into reverse unless pushing shifter down?? what scares me is 6th and reverse are so close to eachother and now that im pushing shifter down to put into 6th i dont want to be doing 80mph and accidently hit reverse!