I have been invited to 1st round interviews from a Middle East office of a consulting firm a couple months ago, however no specific interview date has been scheduled yet.
I tried to reach HR by phone, since they're either responding late or not at all to emails, twice, but the front office did not want to contact me with them and just told me to send an email.
Recently I was lucky that the person who picked up the phone at least gave me the email address of a recruiter, after I explained her that I got an offer from another firm with a decision deadline.
I sent an email to the recruiter immediately. However, in case she does not respond within 1-2 days (since the deadline of the other offer is relatively close), I thought about contacting her on LinkedIn and explaining the situation (I found her profile).
Would this be unprofessional, even in this case, so that it would harm my chances?