I have been using Tresiba for over a year now and I have not had any issues. Since I only use it once daily in the morning I rarely carry it with me. It stays on my night stand, unless I think weather will prevent me from coming home from work or something similar.
I know the NovoLog pen is somewhat different as it is 1 unit instead of 2 units per click, and I have been using the NovoLog disposable pen for about 15 years and never had any issue even once, and I have more stuff in my pockets than most women have in there purses.
That said, unless you have been very unlucky, you want your pen to be reliable. It is one thing that you can have it replaced, another that you may not be able to get the insulin you need, especially if traveling (BTW: I always carry at least one more pen than I expect to need of both Tresiba and Novolog when I travel, especially in case I lose one....)! So even though I have had no bad experiences, I would love to hear what experiences other may have had.