If a timing belt isn't properly installed, could it be the b

If a timing belt isn't properly installed, could it be the because of engine problems two months later?
the garage tells me the timing belt was ok, but to have engine problems just some months afterward is bizarre
are they lying to me to protect themselves? or if the timing belt was the problem, it could happened earlier?

if it had not been put on right, you could noticed it now,the car would not have run good at all,it may be coincidental that it acted up two months afterward,but if they had not got it on right, it could have shown up much sooner than this,the engine problems your having now may not be related to the belt at all,good luck with it.

been a certified mechanic for 37 yrs.

If the belt wasn't installed properly you could noticed a big problem when it came back from the shop. It may be a connection that fell separately or they messed up something else when they fixed the belt.

what problems are you having with the car now? what kind of car,make model year engine etc?