review on certiorari under Rule 45 of the Rules of Court. As a rule, only questions of law, not questions of fact, may be raised in a petition for review on certiorari under Rule 45. However, this principle is subject to recognized exceptions. In the labor law setting, the Court will delve into factual issues when conflict of factual findings exists among the labor arbiter, the NLRC, and the Court of Appeals.[31] Considering that in the present case there were differing factual findings on the part of the Court of Appeals, on one hand, and the Labor Arbiter and the NLRC, on the other, there is a need to make our own assiduous evaluation of the evidence on record. As the two issues raised by petitioner are intrinsically related, they will be discussed together. The Court finds merit in petitioner's contention that it would be more in keeping with the interest of fairness and substantial justice for the Court of Appeals to likewise admit and review petitioner's evidence despite being submitted only on appeal. There appears to be no justification for relaxing the rules of procedure in favor of the employer and not taking the same action in the case of the employee, particularly in light of the principle that technical rules of procedure shall be liberally construed in favor of the working class in accordance with the demands of substantial justice.[32] We have also previously held that "[r]ules of procedure and evidence should not be applied in a very rigid and technical sense in labor cases in order that technicalities would not stand in the way of equitably and completely resolving the rights and obligations of the parties."[33] In line with the objective of dispensing substantial justice, this Court has examined the evidence belatedly submitted by petitioner to the Court of Appeals. Unfortunately, even with this procedural concession in favor of petitioner, we do not find any sufficient basis to overturn the Court of Appeals' May 31, 2005 Decision on the merits. To recall, it was petitioner's assertion in his Position Paper that he is entitled to US$80,000.00 as medical unfitness benefits under Article 20.1.5 of the CBA with AMOSUP, which provision he merely quoted in his pleading.[34] The Labor Arbiter awarded the amount of US$80,000.00 as permanent medical unfitness benefits, citing the said AMOSUP CBA as his basis for the award.[35] The Court of Appeals found that such award was not supported by any evidence, in view of petitioner's failure to present a copy of the AMOSUP CBA and proof of his membership in said union. Although petitioner was able to submit to the Court of Appeals copies of his identification card as an AMOSUP member and a certification from AMOSUP's Legal Department that he was a member of said union during the period of his employment on the M/T Star Langanger,[36] he still failed to present any copy of respondents' supposed CBA with AMOSUP. What petitioner belatedly presented on appeal appears to be a CBA between respondent Masterbulk and the Singapore Maritime Officers' Union, not AMOSUP. Article 20.1.5, or the stipulation regarding permanent medical fitness benefits quoted in petitioner's Position Paper and relied upon by the Labor Arbiter in his