When does "aggressive bidding" cross the line?

We recently were asked to submit a bid to provide the Insulating Concrete Form (ICF) installation for a commercial project in our small town.  We came in as the lowest bidder with Company X, who then lost the job to a large, out-of-state contractor, Company Y.  We were told by Company X that Company Y was given our bid numbers so we would most likely get a call.  Sure enough we did and we provided a new bid and were informed by the project manager for Company Y that we came in the lowest again.  Time passed and no call from Company Y awarding us the job.  Finally, we received a call from one of our flat-work subcontractors who proceeded to read off the bid numbers we had provided to the project manager at Company Y.  He informed us that he was given our numbers and asked to beat them.  In the end, he got the job.

When I confronted the project manager from Company Y and eventually talked to the President of the company who resides and works out of state, he denied that his project managers would do such a thing and was offended at the implication.  He later vowed to fire anyone in his company who engaged in such activity and said he would look into it and get back with me.  To-date he has not.

Note that Company Y's website advertises their aggressive bidding practices.  The question is does giving out a bidders numbers cross the line?  If it does not, why would Company Y deny it?

Another question: do company's truly keep the owners' interests in mind when they try to get the lowest prices?  In this particular case, it appears that the owner was on a tight budget.  Is it wise, in that case to take the risk of hiring a subcontractor who has no experience installing ICFs?  I would think that in itself would be a costly choice.

Lien-waivers for Property Owners...?

A property owner who requested a reimbursement out of his construction loan was asked by the bank's representative to provide a lien-waiver before his request would be processed.  Am I missing something?  Since when can an owner file a lien on his own property?