The fact he was in a union , and did not bother to seek advice seems very strange, as the fact he has not maintained documentation of past disiplinary procedures......
He does not seem to have an opinion either way, fairly non plussed on the issue, again strange for someone who is losing their job.
Apologies if I seem critical, just very little credible information on this dismissal procedure.
As for bullying, if it was severe he would have been given the boot quick, but this has taken 18 months to get to this stage seems fishy , why is this an issue now, after 26 years of employment.
My advice would be to get the Union heavily involved ( contact rep in job, also Union Offices, request a meeting , and sit down and discuss how case has gotten this far, would advise you to be present, your friend has not made a good job of this on his own).
State you will be appealing the warnings (normally given 7 days from letter arriving), and will be taking the matter to LRC / Labour Courts if neccessary.
Keep the thread updated, any specific questions , just pop them in bullet pointed.